Stocks started 2019 on a mixed playing field on Wednesday, but Apple dropped a revenue and earnings warning after the close and that sent equity index futures down over 1% on Thursday morning. Investors have felt the brunt of major selling and volatility, and the pre-2018 trend of buying every dip just has not been working for some time now. Investors now have to rethink how to position their investments and assets for 2019.

24/7 Wall St. reviews dozens of analyst research reports each day of the week in an effort to find new ideas for investors and traders alike. Some of these analyst reports cover stocks to buy, while some cover stocks to sell or to avoid.

Additional commentary has been added on most of the daily analyst reports, along with trading history. The consensus analyst price targets and other valuation metrics are from the Thomson Reuters sell-side research service.

These are the top analyst upgrades, downgrades and initiations seen on Thursday, December 20, 2018.

AbbVie Inc. (NYSE: ABBV) was downgraded to Neutral from Buy at Merrill Lynch. It closed down 3.2% at $89.23 a share on Wednesday, in a 52-week trading range of $77.50 to $125.86.

Agilent Technologies Inc. (NYSE: A) was started with a Buy rating and assigned a $77 price target at Needham. The stock previously closed down 2.6% at $65.69, and it had a consensus target price of $79.33.

Albemarle Corp. (NYSE: ALB) was downgraded to Hold from Buy at Berenberg. Shares closed up 1.3% at $78.11 ahead of the call, with a consensus target price of about $120 and a 52-week trading range of $71.89 to $138.67.

Apple Inc. (NASDAQ: AAPL) dropped a bombshell on the markets after Wednesday’s close by lowering revenue forecasts, mainly due to iPhone unit slowness in China and internationally. This was more than a rare move by Apple, even though analyst after analyst in late 2018 was trimming iPhone numbers and revenue/earnings numbers left and right. Macquarie downgraded Apple to Neutral from Outperform and Jefferies downgraded it to Hold from Buy. Loop Capital also downgraded the shares to Hold from Buy. Citigroup maintained its Buy rating but lowered its target to $170 from $200, and Apple was maintained as Buy at Merrill Lynch, with a price objective cut to $196 from $220. Morgan Stanley cut its target to $211 from $236 while maintaining an Overweight rating. More target cuts were seen, and the general theme here should be pretty obvious. The shares closed at $157.92 and were indicated down 8.2% at $145.00 Thursday morning. The prior 52-week range was $146.59 to $233.47. On top of this being a 52-week low, Apple has lost some $300 billion or so in market cap now from its over $1 trillion peak in 2018.

Bio-Rad Laboratories Inc. (NYSE: BIO) was raised to Overweight from Equal Weight with a $315 price target (versus a $228.08 prior close) at Barclays.

Boeing Co. (NYSE: BA) was mentioned in a research note at Robert W. Baird as likely to miss its plane delivery guidance for 2018 when it reports in the coming week. After having 119 deliveries in December, the firm estimates that this was 19 planes or so short of the 2018 target of 810 to 815 planes. Baird further lowered its earnings estimates for the fourth quarter to $4.35 per share from $4.46 and lowered the annual earnings estimate by the same amount.

Canadian Solar Inc. (NASDAQ: CSIQ) was raised to Buy from Neutral with a $19 price target at Goldman Sachs.

Cheniere Energy Inc. (NYSEARCA: LNG) was started with a Buy rating and assigned a $72 target price (versus a $60.04 close) at UBS.

Cigna Corp. (NYSE: CI) was raised to Outperform from Market Perform at Raymond James. The stock closed at $187.17 on Wednesday and had a consensus target price of $247.21.

Cintas Corp. (NASDAQ: CTAS) was raised to Buy from Neutral at Merrill Lynch.