Several innovations announced by a rival brought some heat to the online travel agency.On news that a very well-capitalized and famous rival is substantially expanding its travel offerings, Booking Holdings (BKNG 4.90%) stock took a hit on Monday. The online travel agency's (OTA) share price dropped by nearly 5% during that trading session, which was a notably more pronounced decline than the 0.9% slide of the benchmark S&P 500 index. A competitor gets more competitiveThat rival is no less an enterprise tha ...