Protocol · August 1, 2017
BIP 148 UASF flag day pressures SegWit activation
Price at event
$2,747
Today
$73,594
Since then
×26.8
On August 1, 2017 (00:00 UTC), nodes running the BIP 148 user-activated soft fork began rejecting any block that failed to signal SegWit support, a deliberate threat to orphan non-compliant miners. The brinkmanship worked without the flag day ever firing in anger: miners scrambled to lock in SegWit via BIP 91 days earlier, and SegWit formally activated later that month. It remains the canonical example of economic nodes, rather than hashpower, dictating a Bitcoin upgrade.
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