Thursday was a broad down day for U.S. equities, led lower by the energy sector, which faltered by 1.3%. The S&P 500 lost 0.2% and the Nasdaq Composite fell 0.4%, though the Dow Jones Industrial Average managed to finish the day with marginal gains.

As we enter the final trading day of the week, the spotlight again falls on a trio of stocks following their quarterly earnings reports. Applied Optoelectronics Inc (NASDAQ:AAOI), GoPro Inc (NASDAQ:GPRO) and Shake Shack Inc (NYSE:SHAK) are all worth keeping an eye on Friday.

Here’s what you need to know.

Applied Optoelectronics Inc (AAOI)

One of Wall Street’s hottest stocks in 2017 is getting hammered following its second-quarter earnings report.

Applied Optoelectronics — a fiber-optic component supplier — actually put up Street-beating results for Q2 that were far wider than analysts’ expectations. Earnings of $1.54 per share were 862.5% better year-over-year, and easily trounced Wall Street’s projections for $1.32 per share in profits. AAOI’s revenues of $117.4 million were a 112% year-over-year jump that beat estimates for $116.3 million.

However, the company expects “softer-than-expected demand for our 40G solutions with one of our large customers that will offset the sequential growth and increased demand we expect in 100G,” and thus delivered disappointing Q3 guidance. Specifically, the midpoint of the company’s projected earnings range of $1.30-$1.43 per share fell far below Wall Street’s estimates for $1.31 per share, and AAOI revenues of $107 million-$115 million are far below the $123 million analysts expected.

AAOI stock, which had more than quadrupled in 2017 alone, is losing a massive chunk of those gains this morning, off 27% in Friday’s morning trade.

GoPro Inc (GPRO)

GPRO stock, meanwhile, is poised to make one of its biggest single-day gains of the year following its Q2 results.

The action-camera maker unveiled a loss of 9 cents per share — narrower than the 25-cent loss expected by Wall Street’s pros, and significantly better than the year-ago adjusted loss of 52 cents. Meanwhile, revenues of $296.5 million were better by 28.4% year-over-year and topped estimates of $269.9 million. Over half of the country’s revenue was brought in from markets outside the U.S.

Higher demand for GPRO products, as well as cost-saving initiatives, helped drive better margins and profits for the period.

Things looked rosy going forward, too. GoPro is projecting earnings in a range of a 1-cent loss to an 11-cent profit for the current quarter; analysts were looking for a 12-cent loss. Meanwhile, GoPro’s revenue range of $290 million-$310 million was more than enough to top the consensus estimate of $278.5 million.

GPRO shares are surging more than 15% ahead of Friday’s bell. That should reverse a 5% year-to-date loss and send the stock back into the black for 2017.

Shake Shack Inc (SHAK)

Shake Shack’s lousy year looks set to continue Friday following (and despite) the company’s second-quarter earnings beat.

The burger chain earned $4.9 million for the second quarter — a 48% year-over-year jump from the $3.3 million it earned a year ago. On an adjusted basis, profits of 20 cents per share were 4 cents better than Wall Street’s estimates.

Revenues were just as good, climbing 37% year-over-year to $91.3 million, good enough to beat analyst expectations for $89 million. That came on a same-store sales decline of 1.8%.

What’s hampering SHAK shares this morning are Q3 expectations. Shake Shack says full-year comps are on track to decline 2%-3% year-over-year. Moreover, a projected revenue range of $351 million-$355 million came in below Wall Street estimates for $356.7 million.

SHAK shares are down fractionally this morning, which should keep the stock mired in a losing year-to-date effort.