Jamie Dimon has floated the idea that he may consider leaving if his role is split. We noted that one analyst recently signaled a $20 billion or 10% risk that could come out of the stock if Dimon decided to leave the firm if his role is split. We have also warned of a coming activist investor bubble that seems to be forming as activist investors are attacking billions and billions worth of companies if you count the market caps.

Dimon has maintained that the issues behind the London Whale have been resolved. Unfortunately, many top lieutenants have left the firm in recent months. While this may be a sign that things were not as good as some analysts hope, this also has created a bit of a management vacuum and that leaves no heir apparent if Dimon chooses to just leave J.P. Morgan.

Warren Buffett of Berkshire Hathaway Inc. (NYSE: BRK-A) has taken sides, saying Jamie Dimon is one of the greatest bank CEOs that exists. Ken Langone, a founder of Home Depot Inc. (NYSE: HD), also has been in full support and said that he would sell J.P. Morgan shares if Dimon leaves. Citigroup Inc. (NYSE: C) recently talked up its own split role position. The bank said that the split of a chairman and CEO role have worked well for it during the restructuring.

J.P. Morgan remains one of our top banks as one of the seven safest banks in America for 2013. Unfortunately, the London Whale issue and the loss of Jamie Dimon’s ability to speak against regulation and legislation has taken the bank’s leadership role away.

So, tell us what you think in our anonymous poll below.

The numbers are truly impressive. The AAR counted 259,141 petroleum carloads last week. Just over a year ago, the count was just shy of 120,000 carloads for the comparable week. And that represented a rise of nearly 30% from the same week in 2011. Rail transportation of crude oil and petroleum products has nearly tripled in three years.

Coal shipments by rail still outnumber petroleum shipments by about eight to one, but coal carloads are down 5.6% year-to-date, compared with last year. And the number of carloads of grain has fallen 16% in the same period.

Among the railroads, the big winner is the Burlington Northern Santa Fe (BNSF), which is owned by Warren Buffett’s Berkshire Hathaway Inc. (NYSE: BRK-A) and plies the rails along the northern tier, including the oil-producing states of North Dakota and Montana. Railroads that depend more heavily on coal shipments, like CSX Corp. (NYSE: CSX), Norfolk Southern Corp. (NYSE: NSC) and Union Pacific Corp. (NYSE: UNP), have all experienced double-digit percentage drops in coal ships, weighing on revenues and profits.

To keep things even for U.S. investors, we screened out the ADRs held by Buffett and Berkshire Hathaway Inc. (NYSE: BRK-B) even though one is mentioned at the end of the screen to keep them on the list. Of the dozens of stocks held by the conglomerate, these are the eight highest dividends in the Buffett portfolio. We have put the stocks in order of the highest yields first and added in color on each if applicable. As you will see, most of the Buffett top dividend yields still offer upside to their consensus price targets for value investors looking for growth.

ConocoPhillips (NYSE: COP) leads the list with a common stock dividend yield of 4.2%. The company has pledged to keep its dividend strong, and this puts it higher than other oil giants. This stock is now within about 1% of new 52-week highs and the $62.42 share price compares to an analyst consensus price target of about $63.98.

Gannett Co. Inc. (NYSE: GCI) has a surprising yield of 3.6% for its common stock holders. This remains a small holding of Warren Buffett but investors might be surprised that the newspaper and media stock has risen to the point that it is up almost 100% from its 52-week low. At $21.62 as of now, the stock trades right at the $21.61 consensus analyst price target, and the 52-week trading range is $12.17 to $22.21.

General Electric Co. (NYSE: GE) offers a 3.3% yield, partly because shares have pulled back since earnings. The earnings report was not stellar by any means, but we think GE shares were sold off too hard after earnings when you consider the state of the bull market. Shares are at $23.24, and GE’s 52-week high is $23.90. Analysts have a consensus target price of $25.33. GE is likely to have a dividend hike yet again later this year.

Wells Fargo & Co. (NYSE: WFC) is a top bank and Buffett keeps buying more and more of this stock each and every quarter. The 3.2% common stock yield is rather impressive, and this remains at the top of the seven safest banks in America. This bank is challenging the highs from before the recession again, if you back out the dividend payments. At $39.30, its stock hit that multiyear high on May 15, and analysts have a consensus price target of $40.76.

Procter & Gamble Co. (NYSE: PG) has lifted its dividend and is yielding 3.1% after a dividend hike in April. Buffett has trimmed the stake here over time, but activist investors have been on management’s back and pressing it to run the company better. If P&G keeps up its efforts, it could be worth even more. The market cap of $221 billion already makes it one of the largest public companies out there. With shares at $80.68, the consensus analyst target price is $82.78.

J.P. Morgan Chase & Co. (NYSE: JPM) is a personal holding of Warren Buffett rather than Berkshire Hathaway. The bank pays a 3.1% dividend, despite not getting to be as aggressive on its capital plans. Jamie Dimon has been under fire here to split the CEO and chairman roles, but Buffett recently has praised Dimon as a great CEO who also deserves his chairman role. We would caution that one analyst showed that some $20 billion (10% of the share price) could come out of the stock if Dimon leaves the bank because there is a management replacement vacuum right now with no heir apparent. With shares at $51.09, the consensus analyst target is $56.21.

Johnson & Johnson (NYSE: JNJ) recently raised its dividend. The drug and consumer products giant has been a habitual dividend-raising machine, and its product quality controls appear to be over. The 3.1% payout is impressive when you consider that this stock just hit an all-time high on May 15. Note that the consensus analyst price target of $86.50 is actually less than the current price of $87.64.

United Parcel Service Inc. (NYSE: UPS) ranked as number eight with a dividend yield of 2.8%. This comes as the stock is challenging all-time highs, and the shipping giant has raised its dividend payment consistently. With shares at $88.60, analysts have a consensus price target of $93.09 on the stock.

GlaxoSmithKline PLC (NYSE: GSK) is the ADR of the group, and it was only included because it screens out as having such a high yield at 4.3%. That would have put it at the top of the list. As this is an ADR and subject to currency changes altering the payouts each time in dollars for ADR holders, we are only representing the Yahoo! screen for the nominal payout rather than adding color here.

Jon C. Ogg

*The full Buffett and Berkshire Hathaway portfolio can be seen here.

The new Buffett holdings are below.

American Express Co. (NYSE: AXP) was roughly 151.6 million shares, SAME AS last quarter.

Bank of New York Mellon Corp. (NYSE: BK) was almost 19 million shares, which appears to be slightly lower but it had been raised before. What matters here is that it remains a substantial holding still.

Chicago Bridge & Iron Co. (NYSE: CBI) was a NEW POSITION at just over 6.5 million shares worth over $400 million.

Coca-Cola Co. (NYSE: KO) was more than 400 million shares due to the stock split of 2012, but this is virtually the SAME AS BEFORE.

ConocoPhillips (NYSE: COP) is the SAME POSITION at 24.1 million shares, but this is lower than in prior quarters.

Costco Wholesale Corp. (NASDAQ: COST) was the SAME POSITION at 4,333,363 shares.

DaVita Inc. (NYSE: DVA) was a LARGER POSITION and already more than a 10% stake and we recently saw that Berkshire Hathaway had entered into a standstill agreement not to buy more than 25% of the company after already having increased its stake recently. This was listed as 14.97 million shares as of March 31 versus 13.6 million shares before.

Deere & Co. (NYSE: DE) was the SAME POSITION at roughly 4 million shares.

DirecTV (NASDAQ: DTV) was HIGHER YET AGAIN at 37.275 million shares versus almost 34 million shares and that was also higher than before.

Gannett Co. (NYSE: GCI) was the SAME POSITION of 1.74 million shares.

General Electric Corp. (NYSE: GE) is listed as the SAME POSITION at 588,900 shares, but this is still way down from prior reports.

General Motors Co. (NYSE: GM) is the SAME POSITION at 25 million shares, but this was previously up from smaller positions.

GlaxoSmithKline (NYSE: GSK) is the SAME POSITION at 1.51 million shares.

Investors used to be addicted to stock splits for more than a generation. As share prices rose and rose, companies kept splitting their stock. Some consider this a means of keeping a share price low to keep attracting new investors. Other investors consider a stock split nothing but a gimmick.

Whole Foods Market Inc. (NASDAQ: WFM) was the latest company to join in on the bandwagon. The stock rose by 10% and hit yet another all-time on the news. The reality is that the shares have risen on a solid earnings report and on its ability to maintain much higher gross margin than traditional grocery stores.

Other companies have upcoming stock splits as well. The earnings calendar and stock split calendar show that A.O. Smith (NYSE: AOS) and Colgate-Palmolive (NYSE: CL) will both go ex-split on a 2-1 basis with an ex-split date of May 16. Noble Energy, Inc. (NYSE: NBL) will go ex-split on a 2-1 basis on May 29.

Ask Warren Buffett what he thinks about stock splits. His A-shares of Berkshire Hathaway Inc. (NYSE: BRK-A) have never split and recently put in an all-time stock price high of almost $167,000. Even his more newly created B-shares of Berkshire Hathaway Inc. (NYSE: BRK-B) trade at a high price of $110.00.

Many companies do not like to split their stocks. Apple Inc. (NASDAQ: AAPL) might greatly benefit from this as it is more expensive to buy share of common stock than it is to buy an iPhone or an iPad. Still, its shares went to above $700 and the sell-off down to under $400 was never really directly attributed to Tim Cook not splitting the stock.

What about Google Inc. (NASDAQ: GOOG). Its stock just hit a new all-time high of $873.50 on Tuesday and this company’s efforts were being aimed at a split that was actually a division of power more than a traditional stock split investors are used to.

Some investors love stock splits. Others think of them as mere gimmicks. The debate remains alive, but as share prices rise and rise there will likely be more and more stock splits coming down the pipe. We have considered this merely as a poor man’s dividend. When you see stock split after stock split being announced, you generally know you are deep into a bull market.

Bloomberg covered the comments by Buffett, CEO of Berkshire Hathaway Inc. (NYSE: BRK-A):

“We’re not buying bonds of Apple — we’re not buying bonds of anybody,” Buffett said on May 4. “It has nothing to do with them being a tech company. The yields are too low.”

The news service made the following calculation:

Apple’s debt sale included $4 billion of 1 percent, 5-year notes that pay 40 basis points, or 0.4 percentage point, more than similar-maturity Treasuries (USGG10YR); $5.5 billion of 2.4 percent, 10-year securities with a relative yield of 75 basis points and $3 billion of 3.85 percent, 30-year bonds paying an extra 100 points.

This continues a trend whereby large successful American companies can borrow at super low prices, often to buy up shares and increase dividends. A number of analysts have pointed out that the strategy only works if the cash flow of these public companies can cover their borrowings year in and year out. A downturn in cash flow because of a recession, or a drop in earnings because of competition or rising expenses, could drive dividend payments back down.

The search for higher yields and increases in equity value have pushed many stocks higher. Buffett has elected to invest in equities and derivative instruments. It would be ironic if low yields that lead to borrowing to increase corporate dividends eventually overwhelms company treasuries and becomes a cause for pulling the stock market back down. At that point, Buffett might look back and decide those Apple bonds were a good deal.

Bain and Golden Gate are close to a $6.4 billion buyout of BMC Software Inc. (NASDAQ: BMC). (Reuters)

Google Inc. (NASDAQ: GOOG) Android opens an app store in China. (Reuters)

Sales of the Toyota Motor Corp. (NYSE: TM) Camry and Honda Motor Co. Ltd. (NYSE: HMC) Accord are hurt by new competition from U.S. car manufacturers and Hyundai. (WSJ)

“Iron Man 3,” released by Walt Disney Co. (NYSE: DIS) studios, sets weekend records with $175.3 million in ticket sales in North America. (WSJ)

Norway may increase its taxes on oil production. (WSJ)

Neiman Marcus Group may set an initial public offering. (WSJ)

Institutional Shareholder Services tells J.P. Morgan Chase & Co. (NYSE: JPM) stockholders not to vote for the three members of the bank’s risk management committee. (NYT)

Buzzfeed will try to expand its foreign news content. (NYT)

President Obama may support the export of natural gas. (FT)

The European Union could put a 40% tariff on Chinese solar panels. (FT)

YouTube may start to charge for some video channels. (FT)

Berkshire Hathaway Inc. (NYSE: BRK-A) will not buy Apple Inc. (NASDAQ: AAPL) bonds because of their low yields. (Bloomberg)

Many of the world’s largest carriers will not sell the iPhone because of the fees Apple wants to charge them. (Bloomberg)

The conglomerate is set to report earnings on Friday ahead of the annual meeting, but earnings do not really matter here. Mr. Buffett has said over and over that Berkshire Hathaway could make its earnings magically go up or down based upon purchase or sale transactions. He maintains over and over that the book value per share is what really matters here. As always, Berkshire Hathaway Inc. (NYSE: BRK-B) and Warren Buffett’s latest full stock holdings can be tracked here.

These are the portfolio changes that 24/7 Wall St. believes Mr. Buffett and portfolio managers Todd Combs and Ted Weschler have made ahead of the annual meeting.

Archer Daniels Midland Co. (NYSE: ADM) was a new position at the last report and with Buffett giving more investing money of about $1 billion to Ted Weschler and Todd Coombs lately, our bet is that this position has been added to. ADM was a new position of 5.95 million shares worth some $163.1 million as of the end of 2012.

DaVita Inc. (NYSE: DVA) was already more than a 10% stake and the firm keeps raising its stake. Frankly, we would not be shocked if this company was just acquired outright down the road by Berkshire Hathaway.

DirecTV (NASDAQ: DTV) has been added to and we see no reason that the latest stake of almost 34 million shares would not be added to yet again. The satellite TV provider is up 16% year to date, just hit a new high on Friday and is up by close to 4% since the end of the first quarter.

General Motors Co. (NYSE: GM) has been added to before. It is possible that Buffett is adding to the stake here, although he would likely want to buy these at a discount in the government offering of “Government Motors” stock rather than in the open market.

International Business Machines Corp. (NYSE: IBM) is going to likely keep growing for Berkshire Hathaway as the company keeps buying back stock and recently raised its dividend. Warren Buffett told CNBC, “I won’t be a seller of IBM.” This was over 68 million shares last quarter for a 6.03% stake, and our bet is that Buffett added a bit to it after the stock went on sale after a poor earnings report.

Johnson & Johnson (NYSE: JNJ) is likely to be void entirely now in the Berkshire Hathaway stock portfolio. This was a mere 327,100 shares last time and has shrunk through time. The stake is so small that it was likely just not exited right before the end of the last quarter.

Moody’s Corp. (NYSE: MCO) has been confirmed that the stock holding is shrinking here. Berkshire Hathaway recently sold off about 1.7 million shares of . The position is very profitable for the conglomerate despite the woes of the past for the ratings agency. Buffett’s stake is still over 26 million shares.

Precision Castparts Corp. (NYSE: PCP) was a larger stake last quarter at roughly 2 million shares versus being a new position of 1.25 million shares in the prior quarter. If the new portfolio managers have new funds, they may have added to this even the stock has been range-bound so far in 2013.

Berkshire Hathaway keeps adding over and over to its position of Wells Fargo & Co. (NYSE: WFC) and we expect that to have continued in the first quarter. What is perhaps more interesting is that Bloomberg showed a video with Warren Buffett praising J.P. Morgan Chase & Co. (NYSE: JPM) and CEO Jamie Dimon. Buffett told Bloomberg that he is in full 100% support of Jamie Dimon and his dual role as CEo and Chairman.

The tweet “Warren is in the house” ahead of the Berkshire Hathaway Inc. (NYSE: BRK-A) annual meeting might as well have said “Warren is the house.”  The @WarrenBuffett profile has now gathered a whopping 109,534 followers as of 2:35 p.m. EST on Thursday. You can bet that the number will grow much more, and you can bet that now social media addicts can hear the same canned statements like “America’s greatest days are ahead of it” live on their social media feeds. Our only advice to social media readers is that just because it came from Mr. Buffett doesn’t make it so.

Hopefully Mr. Buffett will not start using Twitter to communicate sensitive financial communication about the economy or about politics and financial history. The public just might forget that Buffett is simply talking up his positions and making sure that investors don’t panic out of their Berkshire Hathaway stock.

Here is the funny thing. Warren Buffett probably had his secretary or someone else do the tweet for him. If Twitter was a public stock, chances are high that traders might have sold into this news. They may have even short sold it.

The U.S. dollar index is trading down 0.28% today, now at 81.521. The GSCI commodity index is down 0.9% at 624.44. WTI crude oil closed down 2.6%, at $91.03 a barrel, following a massive increase in commercial inventories (more coverage here). Brent crude trades down 2.4% at $99.89 a barrel, as the spread between WTI and Brent now falls below $10 a barrel (more coverage here). Natural gas is down 0.4% today at about $4.32 per million BTUs. Gold settled down 1.8% today at $1,446.20 an ounce.

The unofficial closing bells put the DJIA down about 139 points to 14,700.95 (-0.94%), the NASDAQ about 30 points (-0.89%) to 3,299.13, and the S&P 500 fell -0.93% or nearly 15 points to 1,582.70.

There were a several analyst upgrades and downgrades today, including Biogen Idec Inc. (NASDAQ: BIIB) removed from “Conviction Buy” list and cut to ‘neutral’ at Goldman Sachs; Freeport-McMoRan Copper & Gold Inc. (NYSE: FCX) raised to ‘buy’ at Nomura; Berkshire Hathaway Inc. (NYSE: BRK-A) raised to ‘buy’ at Nomura; Amgen Inc. (NASDAQ: AMGN) added to “Conviction Buy” list at Goldman Sachs; and Oil States International Inc. (NYSE: OIS) cut to ‘underperform’ at BMO Capital Markets and cut to ‘market perform’ at Raymond James.

Earnings reports since markets closed last night resulted in some price moves today, including these as of the last half hour of trading: Affymetrix Inc. (NASDAQ: AFFX) is down 8% at $3.35; Bankrate Inc. (NYSE: RATE) is up 14.7% at $15.46; Leap Wireless International Inc. (NASDAQ: LEAP) is down 3.2% at $5.54; Spectrum Brands Holdings Inc. (NYSE: SPB) is down 4.6% at $53.44; Trulia Inc. (NYSE: TRLA) is up 13.1% at $32.86; Vanguard Health Systems Inc. (NYSE: VHS) is down 8.3% at $13.41; ADT Corp. (NYSE: ADT) is down 6.9% at $40.65; Chesapeake Energy Corp. (NYSE: CHK) is down 2.1% at $19.14 (more coverage here); Comcast Corp. (NASDAQ: CMCSA) is up 1.2% at $41.81 (more coverage here); Humana Inc. (NYSE: HUM) is up 4.4% at $77.38; James River Coal Co. (NASDAQ: JRCC) is up 32.8% at $2.19; Mastercard Inc. (NYSE: MA) is down 2.3% at $540.47; Phillips 66 (NYSE: PSX) is down 2.1% at $59.68 (more coverage here); and Viacom Corp. (NASDAQ: VIAB) is up 3.2% at $66.01 after posting a new 52-week high of $69.00 earlier today.

Before markets open tomorrow morning we are scheduled to hear earnings reports from Archer Daniels Midland Co. (NYSE: ADM), Avis Budget Group Inc. (NASDAQ: CAR), CBS Corp. (NYSE: CBS), Facebook Inc. (NASDAQ: FB), JDS Uniphase Corp. (NASDAQ: JDSU), Las Vegas Sands Corp. (NYSE: LVS), Seagate Technology PLC (NASDAQ: STX), Tesoro Corp. (NYSE: TSO), Visa Inc. (NYSE: V), Alpha Natural Resources Inc. (NYSE: ANR), Cigna Corp. (NYSE: CI), Goldcorp Inc. (NYSE: GG), and Monster Worldwide Inc. (NYSE: MWW).

Some standouts among heavily traded stocks today include:

Advanced Micro Devices Inc. (NYSE: AMD) is up 13.1% at $3.19. The chipmaker had no big news today, although it did introduce two new microprocessors and made some pricing changes that indicate that the company’s pricing may have stabilized.

Sirius XM Radio Inc. (NASDAQ: SIRI) is up 3.4% at $3.36 after posting a new 52-week (and 5-year) high of $3.39 earlier today. The satellite radio company posted a second consecutive high today, continuing to feast off yesterday’s earnings report.

Merck & Co. (NYSE: MRK) is down 2.8% at $45.67. The drug maker slid on its lackluster earnings results and took a slice out of its sales and earnings targets for the rest of the year.

Stay tuned for Thursday. We have noted the following events on the schedule (all times Eastern):

• 7:30 a.m. – Challenger job-cut report
• 8:30 a.m. – International trade
• 8:30 a.m. – New claims for unemployment benefits
• 8:30 a.m. – Productivity and costs
• 10:30 a.m. – EIA weekly natural gas storage report
• 4:30 p.m. – Fed balance sheet and money supply