In most cases, the answer is, unfortunately, no. Bids are final because retracting bids can throw a wrench in how the auction is running and can cause complications in the experience of other users and the organization as a whole.
That being said, we've seen cases where someone accidentally bid $1,000 on an item when they meant to bid $100. In cases like this, don't panic! Just send our team a support ticket as soon as you're able, and we'll try to get it resolved quickly.