Investor sentiment is back in euphoric territory with stocks and speculative names surging, but stretched positioning has some strategists on edge.

Computer-driven hedge funds like Qube and Point72's Cubist have posted losses. Executives and experts have theories on why.

The reemergence of meme stock mania last week has professional investors facing a quandary: ride the excitement of retail ...

Julian Lin: One could quibble about the specific definition of a meme stock, as many of the high flyers as of late do not ...