Technology stocks in the U.S. have seen a spike in short-selling since the start of the year, according to financial research firm Markit, which highlighted Tesla as one blue-chip stock that has seen a surge in investors betting against it.
Short-selling is an investment tactic where a speculator borrows a financial instrument, such as a stock, and sells it in the hope of buying it back later at a lower price, thereby making a profit. Markit measures this short interest by calculating the amount of shares that are out on loan.
Its research shows that short interest in the Nasdaq Composite has risen by 10 percent year-to-date, to 2.9 percent of shares outstanding, with investors expecting some of the biggest names in the sector to fall.
"On the larger (capitalized) Nasdaq 100, Tesla has seen short interest surge by a third in the last month to 15 percent of shares outstanding," Simon Colvin, a research analyst at Markit, told CNBC via email. Tesla is now the most shorted company on the Nasdaq 100, he added, after being the fourth most shorted stock a month ago.