$ROKU call prices stream higher

It took just one week for bullish option traders to score big profits in Roku (ROKU).

On Dec. 19, Our tracking systems found that 2,800 Weekly $140 calls expiring this Friday were purchased for $2.16 to $4.00 above open interest of 2,103 contracts with shares at $135.54.

Those calls have traded up to $6.15 so far today, double their average purchase price. The stock rose 7.25% at the same time, illustrating the kind of leverage that can be achieved 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.

ROKU is up 3.47% to $145.00 in morning trading. The video-streaming company’s shares traded back above their 50-day simple moving average for the first time in over a week today.