Shares of short-term rental platform Airbnb (ABNB 5.29%) popped today. Shares were modestly up until around 2 p.m. ET, when the pop became more pronounced. The timing of this pop coincides with a report regarding a new fee that the company is rolling out. And that's likely why Airbnb stock was up about 6% as of 3 p.m. ET. Another fee for Airbnb? A report from Bloomberg points out that Airbnb intends to charge a new service fee to guests starting on April 1. This will be about a 2% extra fee for cross-border ...