NEW YORK, March 24 (Reuters) - Short interest on the

Nasdaq rose 2.5% in mid-March, the exchange said on Friday.

As of March 13, short interest rose to about 19.972 billion

shares, compared with 19.479 billion shares as of February 27.

Investors who sell securities short borrow shares and then

sell them, expecting the stock to fall so they can buy the

shares back at the lower price, return them to the lender and

pocket the difference.

Shorting can also be part of a hedging strategy.