Stocks sold off strongly Tuesday as investors worried that a trade agreement with China may be further off than had been previously expected. The Dow Jones Industrial Average (^DJI -1.63%) and the S&P 500 (^GSPC -1.54%) plummeted, with technology and industrial companies leading the way down and all market sectors in the red.

Today's stock market

Index Percentage Change Point Change
Dow (1.79%) (473.39)
S&P 500 (1.65%) (48.42)

Data source: Yahoo! Finance.

As for individual stocks, Anadarko Petroleum (APC) accepted an improved acquisition bid from Occidental Petroleum (OXY 0.21%), and GW Pharmaceuticals (GWPH) is seeing success with its cannabis-derived drug.

Columns of numbers and downward graph.

Image source: Getty Images.

Anadarko Petroleum accepts sweetened bid from Occidental

Anadarko acknowledged that Occidental Petroleum's revised takeover bid was superior to Chevron's (CVX 1.89%) and served notice that it would terminate the merger agreement it signed with Chevron. Shares of Anadarko were relatively unchanged at $75.81.

The boards of Chevron and Anadarko had agreed to a merger that valued Anadarko at $65 per share in a cash-and-stock deal, but two weeks ago, Occidental stepped in with a bid of $76 per share, more than doubling the cash that Chevron offered to $38. After Anadarko hesitated to accept that offer, Occidental, with some help from Warren Buffett, issued a revised bid on Sunday to increase the cash portion to $59 while reducing the amount of newly issued stock, which eliminates the need for Occidental's shareholders to vote on the matter.

Chevron now has until May 10 to decide whether to make a counteroffer or take a $1 billion termination fee from Anadarko.

GW's Epidiolex has a strong launch and another successful trial

GW Pharmaceuticals, the British biotech that sells the only FDA-approved drug derived from marijuana plants, released a double dose of good news last night and shares rose 1.5%. The company announced strong sales of epilepsy drug Epidiolex after its launch in the U.S. and a successful pivotal trial that could expand the market for it.

U.S. sales of Epidiolex, a pure form of cannabidiol (CBD), were $33.5 million and total revenue in the quarter came in at $39.2 million, more than double the $16.6 million analysts were expecting. The company had a net loss of $50.1 million, an improvement over the loss of $69.5 million in the period a year ago.

The phase 3 trial of Epidiolex was for treatment of seizures associated with tuberous sclerosis complex, a rare form of childhood-onset epilepsy. Patients in the trials had seizure reductions of up to 48.6% versus 26.5% for those on a placebo. GW Pharmceuticals thinks the indication could double the market for the drug with a launch in 2020.

The stock didn't move much given the good news and raised price targets by analysts, but a lot of success had already been priced into the shares, which are up 88% this year.