Just thought of this - at this moment, I regret every exchange of bitcoins for fiat that I ever performed, "locking profit", "dollar cost averaging", etc - had all the good reasons back then at $29, $99, $230. You will, too, eventually, if you sell now. So don't. You have been warned.
I disagree. I don't regret any purchase I've made with bitcoins or any exchange for fiat that was used to make a purchase.
Case in point. I sold about 1.1 bitcoins recently at $280 USD/BTC to buy a transmission jack and a few other handy things. I was low on fiat at the time and needed some dough quick. My clutch is fuxx0red and I don't want to pay someone $900 to fix it. And if I didn't fix it I wouldn't be able to drive to work, and make money with which to buy more bitcoins and watch my net worth increase exponentially. So I'm not sitting here banging my head against the desk thinking "No, that could be worth $445 now! Or $5000 in a month and a half! Nooooooo I've squandered away my retirement fund!" No, I'll just put a few hundred back in BTC in a couple weeks, sure there will be a comparable loss, but not compared to if I was rendered immobile and couldn't go to work.
So you see? No regrets at all.
I bought some gold and silver a while back. Sure, it's in a bear market. But if there was an unknown bug and the bitcoin procotol broke, I'd still have far more than my initial BTC investment. And if I kept cash I'd just end up spending it. Still no regrets. Of course, I'm not buying any more gold or silver right now, but I have just enough so that I wouldn't be jumping off a bridge if Bitcoin broke tomorrow.
Different strokes for different folks. I hope you stop regretting your bitcoin purchases and exchanges! I buy things with BTC when my need for something in the present moment is greater than the potential gain of holding out for the period of time it would take for me to re-invest that same amount in BTC. Simple as that.