DOJ Short-Selling Probe Eyes Bets on Amazon, Microsoft, JPMorgan

Federal investigators searching for collusion among short sellers have posed a surprising question in recent months: Tell us about your trading in companies like Amazon.com Inc., Microsoft Corp. and JPMorgan Chase & Co.

US prosecutors have sent subpoenas that ask about transactions in a variety of blue-chip stocks to some of the same short sellers who previously responded to inquiries about a long list of lesser-known companies, according to people familiar with the matter. Those prior demands were part of a look at how bearish investors gather and publish research about companies with the aim of profiting when stocks ...