The week of May 20 ended with a very mixed bag in performance. The Nasdaq was up 1% and the Dow closed marginally in the red. Investors keep proving over and over that they are willing to buy the big dips. And the “sell in May and go away” seems to not be deterring some of the bargain hunters looking for value and long-term upside.

24/7 Wall St. reviews many key analyst upgrades and downgrades throughout the week — dozens a day and hundreds by the end of each week in total. There remains a huge interest in which oil and gas stocks now offer long-term upside for investors.

One problem many investors are having is that many oil and gas stocks have risen massively from their lows. Some may have even risen by too much. Investors need to keep in mind that many analysts in the oil patch did not adequately brace for the downside that was seen in 2015 and into the start of 2016. many analysts have also been late to change their negative bias in the run-up.

There were key analyst upgrades and positive calls in four oil and gas stocks this last week, and two big downgrades or tales of caution in the oil and gas sector. There were of course other analyst calls, many of which were reiterations with price target changes, but these were the ones which stood out above and beyond the other calls.

Stocks Analysts Say to Buy

Exxon Mobil Corp. (NYSE: XOM) was raised to Buy and the price target was set at $104 at Argus on May 18. Exxon Mobil closed at $89.53 ahead of the call, and Friday’s closing price was $89.74. The Argus upgrade reflects its diverse asset base, secure dividend, cost controls, and favorable valuation versus peers. Exxon Mobil’s consensus analyst price target is now under the current share price at $85.02 and has a 52-week range of $66.55 to $90.40 – with a 52-week high hit on Friday.

Halliburton Co. (NYSE: HAL) received not just one great analyst call for upside, but two this last week. As a reminder, its merger with Baker Hughes Inc. (NYSE: BHI) has now formally ended. Argus sees 25% upside here, maintaining its Buy rating but raising the target price to $48 from $38 in that call. Halliburton was also raised to Outperform from Market Perform and the price target was raised to $49 from $44 at FBR Capital Markets. Halliburton has a consensus analyst price target of $45.33 and has a 52-week range of $27.64 to $46.69.