eBay has rejected a reported $56 billion takeover offer from GameStop, with the source stating that eBay called the unsolicited bid "neither credible nor attractive." Based on the provided text, the key development is eBay’s refusal to engage with the approach. In merger and acquisition activity, an unsolicited bid is an offer made without the target company’s invitation or prior agreement, and a public rejection typically indicates the target sees the proposal as inadequate or not serious enough to pursue.