Cryptocurrency Markets Shocked as CoinMarketCap Removes Korean Exchange Prices Without Warning
CoinMarketCap, arguably the most prominent global index of cryptocurrency prices, triggered a wave of anxiety and anger this morning when it removed a group of Korean cryptocurency exchanges from its price calculations.
Though the change was apparently made at midnight Sunday U.S. EST, CoinMarketCap did not publicize it until midday on Monday, saying that the Korean exchanges showed “extreme divergence in prices from the rest of the world and limited arbitrage opportunity.”
The move resulted in a sharp drop in CoinMarketCap’s measurement of nearly all cryptocurrencies. That gave the impression that a broad market decline, already in progress, had become even more dramatic overnight. As news of the cause for the sharp drop spread Monday, most cryptocurrency prices began recovering losses.
Get Data Sheet, Fortune’s technology newsletter.
The delisting itself seems to have been relatively uncontroversial—as CoinDesk points out, local exchanges can sometimes show sharp divergence from global prices, masking broad trends. According to CoinDesk, the Korean exchanges Bithumb, Coinone and Korbit, which consistently had prices well above the global market, were removed from CoinMarketCap’s calculations.
Ripple’s David Schwartz acknowledged that the new price is “more accurate and meaningful.”
But cryptocurrency watchers on Twitter responded with understandable anger to the lateness of CoinMarketCap’s announcement, calling it “unprofessional” and saying it may have triggered panic selling.
Some went further, accusing CoinMarketCap of market manipulation. That echoes recent suspicion of insider trading by employees of the Coinbase cryptocurrency exchange.
If there’s one clear takeaway from the incident, it’s that the infrastructure of cryptocurrency markets, much like cryptocurrencies themselves, is still evolving, unstable, and subject to shocks based on nothing more than avoidable missteps.