Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Criteo SA (CRTO -1.66%) rose nearly 10% Monday after an analyst reiterated his overweight rating on the stock.

So what: Criteo shares plunged more than 10% following the company's first-quarter results last week, but JPMorgan Chase analyst Doug Anmuth assigned a $44 price target and insisted, "We continue to believe Criteo stands out from other ad-tech names based on its strong growth and profitability."

Now what: To be sure, Criteo did grow revenue more than 60% year over year last quarter, which resulted in adjusted net income that nearly tripled over the same period to $10.6 million. Criteo also increased its fiscal 2014 guidnace for revenue excluding acquisition costs -- which management calls a "key measure" used to evaluate operating performance and provide useful period-to-period comparisons for their core business -- to between $364.5 million and $372.8 million. Previously, Criteo expected 2014 ex-TAC revenue of between $338.4 million and $345.25 million.

But even so -- and as I suggested last week -- investors are still concerned with Criteo's rich valuation and whether its impressive growth is sustainable over the long term. Today's analyst reiteration provided some comfort to those in the bullish camp, and likely caused at least some of Criteo's large group of short-sellers to cover. But in the end, I'm still happy patiently watching this one from the sidelines.