Bitcoin Miners Signal Revolt Amid Sluggish Blockchain

  • ‘Bitcoin Unlimited’ gains support of world’s largest miner
  • Opponents say move could split bitcoin into two currencies

Bitcoin Jumps in Recovery From SEC's ETF Decision

You may not know it by looking at bitcoin’s recent price surge, but the infrastructure underpinning the world’s most popular virtual currency is teetering.

While speculators continue to push the value of the digital money to record highs against the U.S. dollar, the system that verifies bitcoin transactions -- known as the blockchain -- is more backlogged than at any point in the currency’s eight-year history. The number of transactions awaiting verification is up more than fivefold from a year ago, and the jam is forcing users to pay increasingly high fees to speed up confirmations, which in some cases is making bitcoin more expensive to use than Visa Inc. or PayPal Holdings Inc.