$Z bulls double money in a day

Option traders scored big gains today on upside positions opened in Zillow only one session earlier.

Just hours before the company’s quarterly results yesterday, Investitute’s tracking systems flagged the purchase of 2,700 June $35 calls for $2.56 to $2.75 with shares at $34.15. This was clearly fresh buying, as open interest was well above the strike’s existing open interest of 1,054 contracts.

Those calls sold for as much as $5.50 right after the opening bell today, more than twice their purchase prices. The stock rose 15.81% at the same time, illustrating the kind of leverage that can be achieved quickly with options.

Long calls lock in the price where a stock can be purchased, gaining with a rally and providing leverage to the underlying shares. The contracts can quickly lose value if the stock stalls or pulls back but also carry less risk than owning the shares themselves.

Z jumped 5.05% today to close at $36 even. The real-estate company rallied on strong earnings reported after the market closed yesterday.