The DOJ sent subpoenas over the past few months seeking details on transactions in several blue-chip stocks, according to the report that cited people familiar with the matter.

The DOJ last year also issued subpoenas to dozens of firms, including Citron Research and Muddy Waters Research LLC, as it probes potentially manipulative trading around negative reports on listed companies published by some of their investors.

The U.S. securities regulator has also said it has been considering measures that require big investors to disclose more about short positions, or bets that stocks will fall, and the use of derivatives to speculate on stock moves.

The DOJ, Microsoft, Amazon and JPMorgan did not immediately respond to Reuters' requests for comment.

(Reporting by Eva Mathews in Bengaluru; Editing by Vinay Dwivedi)