24/7 Wall St.

Two major online travel agencies reported second-quarter earnings last night, and both were hammered in Wednesday’s trading session.  Priceline Group Inc. (NASDAQ: PCLN) beat on both profits and revenues, while TripAdvisor Inc. (NASDAQ: TRIP) missed on both.

Shares traded down more than 8% on both stocks in the first half-hour of trading this morning, but for apparently different reasons.

Priceline’s net income rose by 24% year over year while TripAdvisor saw net income slide by 21%. Both had big increases in sales and marketing expenses and that may be what is driving investor caution.

The rise of homeowner vacation rental services like Airbnb is forcing Priceline and TripAdvisor to sprint to catch up. Growth in the private accommodation market reached 11% last year, according to a report at the Wall Street Journal, and growth for this year is projected at 8%.

In the hotel accommodation business, where Priceline and TripAdvisor are strongest, 2016 growth came in at 5% and is forecast to come in at the same level this year.

The hotel industry posted revenues of $151 billion last year while private accommodation revenues are projected to come in at about a fifth of that this year. But growth, not size, appears to be the main driver.

To draw more vacationers, Priceline and TripAdvisor are spending more on sales, marketing and technology upgrades. That cuts into profits, even though top-line growth remains steady.

Priceline stock traded down about 8.1% Wednesday morning, at $1,883.84 in a 52-week range of $1,392.44 to $2,044.51. The consensus 12-month price target on the stock is $2,082.00.

TripAdvisor traded down about 7.3%, at $36.63 in a 52-week range of $35.34 to $66.13. The consensus price target is $43.84.