On CNBC's "Fast Money Halftime Report," Pete Najarian spoke about unusually high options activity in Alibaba Group Holding Ltd - ADR BABA and STMicroelectronics NV STM.

Traders were buying the August $250 calls in Alibaba on Tuesday. Around 7,500 contracts were traded and they paid around $12 for them. The trade breaks even at $262 or around 5.5% from the current stock price. Najarian decided to follow the trade.

Najarian has also noticed STMicroelectronics NV STM because it had a big call options volume in the same strike for the second day in a row. Around 10,000 contracts of the August $35 calls were traded on Monday and traders bought 9,000 more of those on Tuesday. They were trading for around 35 cents. Najarian explained that somebody thinks this stock has some upside in the short term.