That's one reason I sold today, rather than holding. That's not to say I don't think it can still go up, but it closed yesterday at $155.90, and next week's $156 calls were at $0.62. Today, it ran all the way to $156.80, and the highest trade on the strike was $0.90. All of the time value, yesterday, and not a whole lot of movement today, given the pop on SPY, and just 10 cents of time value remaining.
I figured it was safer to take a gain now, than wait for more and lose a ton of value if it drops closer to $156.