The short version: the prices you can trade against don't exist naturally — firms put them there, for a fee you pay in the spread, and they are under no obligation to keep doing it. Liquidity isn't a feature of the market. It's a service, and it's withdrawn precisely when you most want it.

The colony is fed by a neighbour. Every evening, same time, two bowls. It has been reliable for years and the cats treat it as a property of the universe — the way rain is a property of the universe, or the sun.

She went away for a week in July. The food simply stopped. Not reduced, not delayed — absent. And the cats sat where the bowls go, at the time the bowls appear, waiting for a thing that had never once in their experience failed to happen.

They had mistaken someone's choice for a law of nature. It's the most common mistake in markets too, and it has a name.

1. What you're actually trading against

When you place a buy order and it fills instantly at roughly the price on screen, you probably imagine another person sold to you at that moment.

Usually not. On most venues, most of the time, you traded against a market maker: a firm whose business is quoting both a bid and an ask continuously, buying from sellers and selling to buyers, and capturing the difference.

They are not predicting the price. They're providing immediacy — the ability to transact now rather than waiting for a natural counterparty. That's a real service with a real cost, and the spread is the fee.

Everything else about their behaviour follows from one constraint: they hold inventory they didn't want, and that inventory has risk.

2. How the business actually works

They earn the spread, many times. A tiny edge per trade, repeated enormously. Nothing about any individual trade matters to them.

They manage inventory, constantly. Having bought from you, they're now long and exposed. They'll hedge it, offset it against the next seller, or skew their quotes to attract the trade that flattens them. Quotes that drift in one direction are often inventory management rather than an opinion.

They widen when uncertain. The spread is priced for risk. Before a major announcement, during a violent move, when order flow starts looking informed, quotes get wider and sizes get smaller. That's not malice — a market maker who quotes tightly into a move they can't read gets run over.

They can simply stop. This is the part that matters to you. On most crypto venues, nobody is obligated to quote anything. Market makers are not a utility. In genuine stress they can withdraw entirely, in seconds, and the comfortable depth you'd been trading against is gone.

3. Why this explains things you've seen

The crash that went further than seemed reasonable. Price doesn't fall because of selling alone. It falls because the bids that would normally absorb selling were withdrawn at the same moment. The gap is the absence of market makers, not the presence of sellers.

The flash wick that recovered in seconds. Liquidity vanished, a market order ate through whatever was left, makers returned, price restored. Nothing fundamental occurred. Plenty of stop-losses were triggered, which is the connection to the piece I wrote on pre-committed flinches.

Why your big order moved the price and your small one didn't. You consumed the available depth and had to reach for quotes that weren't meant for you. The screen price was real for a small size and notional for yours.

Why spreads are wider at 4am. Fewer makers active, less willingness to hold inventory overnight, more risk of being the only one quoting into news.

4. What to do with this

Judge a venue by depth and spread, not volume. Volume can be manufactured; resting capital exposed to being hit cannot. This is the same conclusion I reached writing about reported volume, arrived at from the other direction.

Use limit orders when you're not in a hurry. A market order asks the maker for immediacy and pays for it. A limit order lets you be the one providing it — in effect, you're collecting a little of the spread instead of paying it.

Expect the worst liquidity at the worst moment. Any plan whose execution depends on trading smoothly during chaos is a plan that depends on other people choosing to stay. They may not.

And don't read quote movement as information. A maker skewing their quotes is managing inventory. People build whole narratives out of what is, functionally, a firm trying to get flat.

5. The uncomfortable half

Market making shades into things that are less benign. The same infrastructure that provides liquidity can be used to quote and cancel rapidly in ways that mislead other participants, and in crypto — where much of this is unregulated and unmonitored — the line between providing a market and manipulating one is policed thinly, if at all. Some firms do both. I can't tell you which, and neither can anyone presenting confident claims about it on social media.

Exchanges pay for this, and that shapes what you see. Venues offer rebates and favourable terms to attract makers, because a venue without liquidity has nothing to sell. Some arrangements include tokens, equity, or terms not disclosed to users. The depth on your screen may be subsidised, which means it may also be withdrawn when the subsidy ends.

And "liquidity is a service" cuts against a popular story. Bitcoin's trading infrastructure is substantially provided by a small number of sophisticated firms, which sits awkwardly with the decentralisation narrative. The protocol is decentralised; the market around it is not especially, and the gap between those two facts is where a lot of motivated reasoning lives. It's not a flaw in Bitcoin. It is a reason to be careful about which claims about decentralisation you're actually buying.

The practical consequence is small and boring: if you buy spot on a schedule and self-custody, almost none of this affects you. It matters if you trade, if you use leverage, or if you ever need to move size in a hurry. The quieter your approach, the less you depend on anyone choosing to fill the bowl.

They sat where the bowls go, at the time the bowls appear, for a week. Anything that has always been there is still somebody's decision, and decisions get revised on exactly the day you'd rather they didn't. 🐾⚡