I wouldn't read too much into how much or little the recent chart resembles a rounded top.

I think the point of my comment arose out of the observation that it is extraordinarily difficult to pinpoint a top in real time. I know a guy who has skill at it, but it ain't me. There are things that are what one might call bad omens indicative of a likely top, but they happen too often during an upwards climb of the market to believe any of them. They are particularly common throughout the second half of a long bull. The most reliable of the bad omens that I know about has to do with the market hitting new highs at the same time that market breadth is bad - for example, more stocks are hitting new 52 week lows than 52 week highs for a while, so the climb of the market index is resting on fewer and fewer shoulders. If that's at the same time as rising interest rates, that would be doubly bad. Both situations were in effect before the crash of 1987, for example.

(as for the current situation, breadth has been poor-to-negative in the Nasdaq since around mid December, but the NYSE has been mildly positive the last six weeks or so. But as mentioned, that doesn't mean we're seeing a market top).

So, my original idea is simpler: if a potential index top doesn't get surpassed for a few months, THEN you have an idea that maybe it was "the" top and you could do some selling. The good news being that, because of the "rounded top" observation, the market probably isn't going to be a whole lot lower those few months later, so your waiting hasn't really hurt. If there has been a fresh recent market high, market drops that are both large and lasting are exceedingly rare. The longer it has been, the worse the average returns. Bullishness and the urge to buy on dips die very slowly.

It's possible to do market timing in a somewhat-better-than-random way, but a surer approach is simply valuation. If you own stuff that you yourself believe to be meaningfully overvalued, consider your reasons for holding it. It may be a fine reason (I want it for many years to come), or it might not (I want to eke out the gains from the last little section of this bull market). If Mr Market is offering you a crazy price for something you own, at least think twice before turning him down.

Jim