I dunno. Too many variables to dismiss as horrible out of hand. For one, it depends on the actual companies involved.

Also depends on exactly how he executed it. If the stocks followed the typical average of 10% YoY gains as the rest of the market, then there's a way to execute this strategy wherein he wouldn't lose by definition. For instance, he might set a mark on the sell side to ensure he's not selling at a loss vs. his last buy.

Now, he might get stuck holding the stock for some time (especially after a big downturn) and that might incur him some opportunity cost. But, that wouldn't mean a net loss if he was willing to wait. And, that'd be no different a risk than, say, a typical buy and hold strategy.

"Buying tech stocks" is probably the lucky bit. If the stocks are cyclic but there is a upward trend it probably works pretty well.