Ditto to the responses already. 90% of my investment is in "buy and hold", either blue chip stocks or low cost ETF/LICs. However, I do dabble in other stocks, with the recognition that its very much short term punting, and a bit of market timing. I'm quite frank with myself that these are pretty much gambling, and I track them pretty closely to keep myself accountable.
Most of my speculation has been on ASX listed stocks (I'm Australian after all), and has included:
FKP - bought when then announced a capital raising, sold a couple of days later, +$1082. Had I held to date, I'd have lost -$4628.
VAS (Australian ETF), Sold holding of 900 shares in April. Re bought 1000 shares in June (10% fall), sold August for a total profit (short and long) of +$7553. Alas, if I had continued to hold these, I would be up another $3,500.
BBG two trades on this one, both when it was in the doldrums, sold when takeover proposals received +$3131. I'd be down more than that had I held to completion.
BSL. Took a punt on this one when they did a capital raising, sold off for a loss -$400. Had I held to date, I would have been up +1983.
QBE. Sold and re-bought for a profit of +1750. Market timing.
BLY. Bought after a downgrade, took the dividend and sold for a profit of +$1095. If I'd held to date, would be up another +$3520.
JBH. Bought and sold for a profit of +1034. Holding would have been an additional +$1080
FXJ. Bought and sold for a profit of $267 (really getting out once it broke even again). Holding would have been another +$1700
CSL. This one is open at the moment, I sold off half my holding after the stock rose 80% in a year. Its back down a little, so I'm up $760 on paper so far. If it comes back down a bit more, I'll buy back in.
Overall, I've generally profited from these trades. But with a couple of exceptions, I'd have been better holding these to date, rather than exiting!