June 8 (Reuters) - Shares of Clover Health Investments Corp and other “meme stocks” jumped in premarket trading on Tuesday as small-time individual investors again piled into some of the most heavily shorted U.S. stocks. The social-media driven rally has sent shares of companies including AMC Entertainment Holdings Inc and GameStop Corp zooming this year in a bid to squeeze Wall Street short-sellers, and has prompted the U.S. Securities and Exchange Commission to say it was looking into signs of market manipulation. Medicare-backed insurance seller Clover and electric-truck maker Workhorse Group Inc are among the most shorted stocks across U.S. exchanges, with Clover being the target of short seller Hindenburg in February. Clover’s shares were last up 13.3% at $13.50 after jumping 32% on Monday. Workhorse shares gained 2.5%, while AMC and GameStop rose 4.1% and 3.5%, respectively. (Reporting by Aaron Saldanha in Bengaluru; Editing by Shounak Dasgupta) Our Standards: The Thomson Reuters Trust Principles.