Blockstream CEO Adam Back has issued a stark warning to crypto investors, suggesting that many altcoins and memecoins could be priced near zero as market efficiency improves. In a recent post on X, Back, a staunch Bitcoin advocate, reiterated his long-held belief that the efficient market hypothesis will eventually drive weak crypto tokens towards negligible valuations. He expressed surprise that it has taken this long for markets to "catch up" with what he describes as "air tokens, altcoins, memecoins." Back's comments come amid a market environment where Bitcoin's dominance is near 59%, constraining altcoin momentum. With nearly 40% of altcoins trading close to all-time lows, the market shows limited rotation into altcoins. Memecoins, which rely heavily on community attention, are particularly vulnerable during liquidity tightening. Despite this, the memecoin market remains substantial, with a collective market cap exceeding $34 billion, led by Dogecoin and Shiba Inu. Analysts suggest that for altcoins to recover, Bitcoin would need to stabilize, Bitcoin dominance to decline, and investor risk appetite to increase.