What happened

Shares of Criteo (CRTO -1.46%) fell 24.3% in the first six months of 2019, according to data from S&P Global Market Intelligence, after the ad-retargeting specialist encountered execution issues as it works to implement its multi-solution transformation.

But Criteo's year-to-date story isn't quite that simple. In fact, shares traded modestly higher from the start of 2019 through the first few weeks of March, helped by a stronger-than-expected fourth-quarter 2018 report in February that CFO Benoit Fouilland called an "inflection point in [Criteo's] trajectory."

White and red stock market charts on a blue display, indicating losses.

IMAGE SOURCE: GETTY IMAGES.

So what

But those gains wouldn't last long. Criteo plunged nearly 30% at the end of March as Wall Street generally panicked over reports that Google was deciding whether to make changes to its handling of third-party advertisements in both Chrome and the Google Marketing Platform -- even though, as I pointed out in early April, management had largely dispelled those concerns during Criteo's previous quarterly conference calls with analysts.

Unfortunately, Criteo fell again after lowering its full-year guidance about a month later, not because of changes made by Google, but rather due to "execution issues" that would delay its ability to scale with new capabilities Criteo was building to realize the fruits of its multi-product transition. 

Much to the chagrin of growth-hungry investors, Criteo CEO JB Rudelle said 2019 would end up being "another transition year," and called for revenue this year (excluding traffic acquisition costs) to be roughly flat to up 2% at constant currencies.

Now what

It certainly didn't help when, on June 25, Criteo announced its Chief Operating Officer Mollie Spilman had "decided to leave the company to pursue a new career opportunity" -- a discouraging development that saw shares fall another 7.5% in response.

As it stands, based on its past report timing, Criteo should be poised to release second-quarter 2019 results either late this month or in early August. But given its struggles so far this year, it's no surprise to see shares down big even as the broader markets flirt with fresh all-time highs.