Wait till it’s a good deal, then buy. If it drops some more for a while, who cares? You got a good deal.
It’s very hard to nail a bottom without fibbing.
I tend to buy in steps on the way down, starting when I think it’s a fair/good deal, and ending when I’ve got the biggest position size I want.
With Berkshire at its current price, just under $264 per B share, there is no reason ever to wait for a better price.
I read long time ago the advice: “You want to be selling on the way up and buying on the way down.”
It’s emotionally somewhat hard to do the “This is happening right now on the BRK board. “I could have bought at $280 a week ago.
But now it’s $270. I’ll wait until $260.” BRK might drop to $260, but then are you going to move the goalposts to $250?” thing. In fact a couple of days ago there was somebody who said that she waited for a lower price–and got it-- and thereby saved the equivalent of several months income. Problem is, of course, if you wait too long the price bottoms and you wind up chasing it up and up and up and up.
What I did is set a few GTC orders on BRK.B at successively lower prices in $10 steps. 295, 275, 265, 255. The 275 filled last week, the 265 filled today. No agonizing over “should I pull the trigger at this price”. Set up your targets and get a pleasant surprise when your broker sends you the fill notification.