Today's noteworthy upgrades include: American Tower (AMT) upgraded to Overweight at Morgan Stanley... CBS (CBS) upgraded to Buy from Hold at Pivotal Research... Coupons.com (COUP) upgraded to Buy from Hold at Craig-Hallum... Discovery (DISCA) upgraded to Buy from Hold at Pivotal Research... Endologix (ELGX) upgraded to Overweight from Neutral at JPMorgan... Federal Realty (FRT) upgraded on results, valuation at RBC Capital... FleetCor (FLT) upgraded to Positive at Susquehanna... HollyFrontier (HFC) upgraded to Outperform from Sector Perform at Scotia Howard Weil... Interxion (INXN) upgraded to Buy at Canaccord... KBR (KBR) upgraded to Neutral from Underperform at BofA/Merrill... M.D.C. Holdings (MDC) upgraded to Sector Weight from Underweight at KeyBanc... Oasis Petroleum (OAS) upgraded to Buy from Hold at Wunderlich... Olin Corp. (OLN) upgraded to Positive from Neutral at Susquehanna... Royal Gold (RGLD) upgraded to Buy from Hold at Canaccord... Sabra Health Care (SBRA) upgraded to Buy from Neutral at Mizuho... Sprint (S) upgraded to Outperform from Market Perform at FBR Capital... Stratasys (SSYS) upgraded to Buy from Neutral at Citi... Sun Life Financial (SLF) upgraded to Outperform from Neutral at Credit Suisse... Taylor Morrison (TMHC) upgraded to Buy from Neutral at Sterne Agee CRT... Wendy's (WEN) upgraded to Overweight from Neutral at JPMorgan... WhiteHorse Finance (WHF) upgraded to Outperform from Neutral at Baird... Zoetis (ZTS) upgraded to Outperform from Market Perform at William Blair.

KBR announced it has signed a contract to provide its green ammonia technology, K-GreeN, for Fortescue's Holmaneset green energy project in Norway. Under the terms of the contract, KBR will provide technology license, proprietary engineering design, and FEED support engineering services for the 675 metric tonnes per day grassroots green ammonia plant in Norway.

Bullish option flow detected in SentinelOne with 3,776 calls trading, 1.1x expected, and implied vol increasing over 2 points to 50.36%. Aug-24 35 calls and Apr-24 20.5 puts are the most active options, with total volume in those strikes near 2,700 contracts. The Put/Call Ratio is 0.21. Earnings are expected on May 30th.