Stock futures dipped on Wednesday, driven by technology shares, as a report of tighter restrictions on AI chip sales to China influenced the sentiment. Here are some of Wednesday's biggest gainers and losers: Biggest stock gainers Shares of the social media platform Pinterest ( NYSE: PINS ) jumped nearly 7% after Wells Fargo upgraded the stock to overweight from equal weight due to a "strong catalyst path" over the next six to twelve months, including the upcoming Amazon ( AMZN ) deal. Analyst Ken Gawrelski raised his per-share price target on the stock to $34 from prior $23. upgraded AMZN...