Shares of the maker of the popular "Candy Crush" mobile game have lost nearly a third in value since its high-profile IPO in March.

Despite a $150 million (98 million pound) buyback programme announced in November – a surprise move coming so soon after the IPO - concerns about the company's heavy reliance on its Candy Crush franchise and limited visibility on future game releases have weighed on shares.

"There is lot of pent-up demand at this point in time, and expectations are very high for King to put up some good numbers,” said Adam Sarhan, chief executive of Sarhan Capital in New York, who does not own the shares.

And there is huge expectation for a large move in the shares after the earnings report.

On Tuesday, the skew in King's options, or the difference in the implied volatility of the options expiring on February 20 and those expiring on March 20, indicates that the stock could move as much as 19 percent, said Fred Ruffy, options strategist at WhatsTrading.com.

Activity in King's options was brisk, with volume of about 18,000 contracts, or nine times normal. Calls, used to make bullish bets, outnumbered puts by a ratio of 10 to 1, the biggest margin on such heavy volume since December, according to Trade Alert data.

"What you are seeing is large investors stepping up and placing significant bullish bets for the stock to rally post earnings,” said Sarhan.

Calls betting on the shares rising above $15.54 by February 20 were the most active, with volume of about 12,000 contracts.

Some of the call activity may be short sellers using call options to hedge their bets, said Fred Ruffy, options strategist at WhatsTrading.com.

A post-IPO lock-up on insiders selling shares is expected to expire after the earnings report and could put additional pressure on the stock in case results disappoint, Sarhan said.

Short interest in the stock is significant. With so little of the outstanding shares available for trade, about 47 percent of what's available for short bets are being borrowed for such a purpose, according to Markit, which tracks brokerage lending programs.

(Reporting by Saqib Iqbal Ahmed)

By Saqib Iqbal Ahmed