Feb 16 (Reuters) - Hedge fund Maplelane Capital has raised its bearish options bets on GameStop and American Airlines, companies that were at the heart of a retail-investor-led rally in heavily shorted stocks, a regulatory filing showed on Tuesday. Maplelane also disclosed that it had put options on 800,000 shares of Bed Bath & Beyond Inc as of Dec. 31, 2020, according to the filing. bit.ly/2Zj3AKP A put option gives the holder the right to sell an asset at a specified price and is often used as protection against a slide in the market. A retail-trading boom - fueled by online discussion forums such as WallStreetBets - drove volumes in U.S. equity options to a record monthly high in January, and some investors may now be turning to put options as an alternative to shorting, analysts Maplelane disclosed that it had put options on 1.6 million Class A GameStop shares at the end of December, compared with 1 million shares in September. On American Airlines, it had put options on 5.5 million shares, compared with 3.2 million shares at the end of September. Maplelane Capital, which has bet against GameStop, lost roughly 45% in January, Reuters had reported, citing a person familiar with the fund"s returns. reut.rs/3b9fegS (Reporting by Noor Zainab Hussain in Bengaluru; Editing by Anil D"Silva)