I just read that stablecoins are only about 1.4% of US M2 money supply. That number stuck with me because it's so small. Every dollar of stablecoin circulating today is a sliver of the actual money in the system. Not 30%, not 10. Roughly one and a half percent.
I think we're nowhere near the start. And I think x402 paired with crypto rails is going to be the infrastructure most of this gets built on.
Coinbase shipped x402 last year, which sounds like a boring protocol thing but is actually the rails for what's coming. HTTP 402 was the "Payment Required" status code that's been sitting in the spec, unused, for thirty years. x402 finally turns it on. An agent hits an API, the API says "that'll cost you $0.003," the agent pays in stablecoin, gets the data back. No API key, no subscription, no human in the loop. Just a transaction.
That last part is the unlock — real microtransactions, where three-tenths of a cent can actually move between two pieces of software and settle in seconds with a fee structure that makes the math work. Credit card rails couldn't do this, which is part of why subscriptions became the default; it was a hack we settled for because the underlying payments didn't fit. Now they do.
What I'm trying to position around is what comes next. Agent-to-agent commerce. Human-to-agent commerce. Agents buying compute from other agents. Paying a research agent a few cents to go pull and synthesize a thing. Subscribing to a data feed at the granularity of "I need this for the next 90 seconds." All of it settling in stablecoins because they're the only thing that moves at the speed agents move.
Existing businesses are going to have to shift their infrastructure to plug into this, and the ones that don't risk getting taken. New businesses probably won't look like the packaged offerings we have today at all. The default shape of software has been a monthly subscription to a bundled product. When agents are doing the buying, they don't want the bundle — they want the one piece they need, right now, at the price it's actually worth.
If stablecoins are 1.4% of M2 today and the agent economy hasn't even started transacting yet, the TAM here is huge.