NEW YORK -- Bullish option traders are piling into E-House China  (EJ) as it rebounds from long-term lows. 

OptionMonster's Heat Seeker system showed heavy buying in the November 10 calls Thursday, most of which were purchased for 30 cents. We sent an alert on our InsideOptions Pro service after about 7,000 had traded but volume continued to build and surpassed 10,000 contracts by the end of the session. There was no previous open interest at the strike, so new money was put to work. 

Long calls lock in the price where investors can buy shares in the extremely volatile Chinese real-estate company. That limits the amount of capital at risk and can result in significant leverage on a%age basis if a rally occurs.

E-House, for instance, was up about 3% when the options began moving and continued rising until finishing the session at $6.75, a gain of 13%. But in that same time, the November calls appreciated more than 30% to 40 cents.  

Other Chinese stocks have been coming to life recently. SouFun (SFUN - Get Report),  which also operates in the real-estate market, saw bullish call buying earlier in the month and huge put selling Thursday. China Unicom  (CHU - Get Report) was targeted on Monday, and Ctrip.com (CTRP - Get Report) call buying from earlier in the month has yield huge gains. JD.com  (JD - Get Report) has been another big winner. 

Investors may also like E-House because it trades for less than book value and is sitting on a boat load of cash. Thursday's overall option volume was 124 times greater than average in the name, with calls accounting for a bullish 98% of the total. 

-- Written by David Russell of OptionMonster

Russell has no positions in the stocks mentioned.