Hedge funds have boosted their bearish bets on Japanese technology companies such as Nikon Corp. and Casio Computer Co. as the industry struggles to deliver the next killer product.

Technology companies account for eight of the 10 Japanese stocks that are most targeted by short sellers, who have collectively wagered ¥197.1 billion ($1.7 billion) that the shares will fall, according to data compiled by Bloomberg.

Camera maker Nikon is the most-shorted stock. Oxford Asset Management, Vinva Investment Management Ltd. and Stats Investment Management Co. are among hedge funds that are wagering against Japanese tech stocks, according to filings with the Japan Exchange Group.