Options on a number of stocks saw a bump in trading volume on Wednesday as fund managers touted their long and short investment picks.

The spike in options activity was particularly noticeable for stocks whose options are usually lightly traded, including Bank Of The Ozarks Inc (>> Bank Of The Ozarks Inc) and Kraton Performance Polymers Inc (>> Kraton Performance Polymers Inc).

Shares of Bank Of The Ozarks fell 15 percent after Muddy Waters' Carson Block revealed a new short position and said the Little Rock, Arkansas-based bank was making outsized loans relative to its assets and was too heavily concentrated in real estate lending. The shares later regained some ground to trade down 4 percent.

Trading in the bank's options soared to 4,800 contracts, about 14 times the average daily volume, as traders loaded up on bearish bets.

Put options betting the shares will dip below $35 by May 20 were the most heavily traded contracts. The shares closed on Tuesday at $39.43 and traded at $37.80 just before the close of the market.

Options volume on Kraton Performance Polymers was similarly high, but on bullish bets, after Rubric Capital Management portfolio manager David Rosen pitched the stock to investors.

Rosen said Kraton Performance Polymers shares were worth $65 a piece, nearly three times the stock's closing price on Tuesday. The shares rose 16 percent to $26.22, a 22-month high. Options volume spiked to 3,100 contracts, eight times what is normal.

Options volume on Anthem Inc  (>> Anthem Inc) was also bigger-than-usual, and trading sentiment leaned bullish, according to options analytics firm Trade Alert data.

Hedge fund billionaire investor Larry Robbins said he is positive on the health insurer and views it as a valuable asset because of its Cigna acquisition.

Options on Alibaba Group Holding Ltd (>> Alibaba Group Holding Ltd) were unusually active with 187,000 contracts traded, or three times what is normal, in mixed trading.

Kynikos Associates founder James Chanos said his firm is still short the Chinese e-commerce company. However, with Alibaba set to report quarterly results on Thursday, it was not clear whether the bump in options activity was due to Chanos' comments or in anticipation of the earnings announcement.

(Reporting by Saqib Iqbal Ahmed; Editing by Steve Orlofsky)

By Saqib Iqbal Ahmed