Risk to hold outweighed risk of selling.

Assume I sold 250 BTC @ 138

If the price goes up to $170 I will probably buy back in and still have the same amount of $.

250 * 138 = $34,500
$34,500 / $170 = 202 BTC (same USD value)

At this point, I feel the risk is higher that the price is going to drop significantly.  I think I'll be buying in somewhere around ~100, which will give me a gain of 100 BTC.

There is no risk for selling now, but there is a risk for holding. Selling everything is always a safe bet.