Altcoin market cap drops by about $200 billion... giving back about two-thirds of the August-September gains

Altcoin market capitalization excluding Bitcoin and stablecoins has fallen by roughly $200 billion, erasing about two-thirds of the $320 billion gained between mid-August and late September, according to CryptoQuant analyst Darkfost. The decline reflects mark-to-market valuation losses rather than equivalent cash outflows or realized losses. On Binance, the share of altcoins trading below their 200-day moving average dropped from 82% in mid-August to 10% in early October before rebounding to around 70%, signaling renewed technical weakness across the altcoin complex. The reversal matters because it shows how quickly the summer rally has unwound, leaving most traded altcoins back below a key long-term trend gauge. Traders will watch whether the below-200-day share keeps climbing toward August levels, which would confirm broadening downside momentum.