Ask HN: How can Coinbase make good on deposits/withdrawals?

Coinbase can use (and runs) an exchange to get liquidity. When a user sells their coins, Coinbase goes to an exchange and sells them on, taking a cut.

That's why Coinbase runs GDAX that caters to large & frequent traders, giving huge discounts on fees to the people who provide that liquidity for them. They also run an OTC desk to shuffle funds around in larger quantities both for themselves and their largest customers.

What is "the market"??? It's only people agreeing to trade... so vendor AND buyers!! What makes a "market price"? It's the amount that buyers are willing to give to sellers for something. If there is no buyer (or no sellers ), then there is no "price", because there is no market. Same if buyers and sellers cant agree on the price (vendor ask to much) Coinbase is only a marketplace. So it doesn't have to honor any deposit. It only allows sellers and buyers to trade

Ultimately you don't sell your bitcoins to Coinbase. You sell them to the people who are buying bitcoins on Coinbase. The point where buyers and sellers meet is the current price on Coinbase.

From my understanding (which may be entirely wrong but it's not like that stops people on the internet from writing things as if they're correct in all knowledge), Coinbase itself does not give you the $10,000 when they sell. Rather, they are merely a pretty front end for a standard exchange; probably GDAX, the one they also own and operate. So when you go to their site and tell them to give you $10,000 for your 1 BTC, what they actually do is go to their exchange and create a sell order on your behalf. When that order is fulfilled by someone else buying 1 BTC for $10,000, Coinbase takes a cut and then puts the rest into your account.

To get your fiat cash out, you'd have to sell that 1 BTC for $10,000. Someone needs to be on the other side of that trade buying it. You get their $10K, and they get your 1 BTC (and coinbase takes a small percentage for facilitating the transaction).

If nobody wants to buy your BTC at $10K, you don't get "your" money out, until coinbase can find a buyer to match with your sale.

In your example, all 10 of you start lowering your asking price, and "the market" goes down until you make a sale.

Coinbase may provide some liquidity, buying your BTC at "market price" with their cash reserves, but only if they think they can resell it at a higher price.

The risk they take on in doing that, and the liquidity they provide, is the nominal economic reason you are paying their fees.

Replace BTC for EUR, CHF, GBP or any other currency (or even a physical good, like an ounce of gold) and see what changes. The fact that BTC is a cryptocurrency doesn't change anything in how trades happen. And the fact that 1BTC used to be 10USD but now is 10k USD is no different than 1USD being 0.95EUR one year ago and 0.85EUR today. The difference is larger, yes, but that doesn't matter.

Coinbase's exchange GDAX matches sellers with buyers. The buyers bring the cash to the party, not Coinbase.

When you buy or sell on an exchange, you're not transacting against the exchange, but against a counterparty, via the exchange; someone like you, but making the opposite transaction. If you sell a Bitcoin for $10k, then someone else brought $10k to the exchange and offered to exchange it for a Bitcoin.

The only way an exchange wouldn't be able to honour deposits is if they lost them, or because of fraud. A surge in price shouldn't affect the solvency of the exchange.

I think people forget - Coinbase makes profit in BTC too.

The issue of disbursement might have happened if they were completely USD or fiat business and the market ran away from them during conversion. But btc fees has them covered.

Remember: you don't have to do your transactions in whole bitcoins.

I, for instance, had .32btc sitting around on Coinbase and decided to sell it when the price broke 10k. That got me about $3k.

The confusion results from the conception that the market (any market) has a single price. It doesn't. When exchanges (stock exchanges, currency exchanges, commodity exchanges) execute trades, they do so with something called an "order book". You can think of it more like an available histogram of potential trade prices. The transactions tend to settle at the nexus of where buyers meet sellers, but if there's only $1 worth of BTC available at the "1 BTC=$10000" rate, then if you want all of your $10 transaction to execute now you will have to pay more. Alternatively you can leave your order at the "1:10000" rate and hope that someone comes and picks it up.

Coinbase is just a broker with a bunch of customers. It connects to all the BTC exchanges in order to execute all their orders. They don't own bitcoins.

Many thanks to all these responses. I know this question has been hashed out ad nauseam on HN but given the dramatic rise over the last week, I needed a reality check that im not missing something. I find this discussion interesting.

Screenshot of Coinbase quote before the site crashed this morning before price "fell" "back" to $16,000. https://imgur.com/a/FClNZ

Coinbase is an automated mechanism that matches buyer to seller, although it does you the extra favor of storing your private keys for you (something a lot of people don't trust, probably for good reason).

I don't know what external hooks there are that add liquidity, perhaps some of the other exchanges including the one it owns. Otherwise it would feel more like an E-Bay auction than a fast-paced market.

If everyone withdraws at once, you'll have 10 sell orders at the same time that need to be filled 'someplace' on the other side.

If no one wants it anymore, the asking price will have to get lower and lower. Coinbase shows you some sort of average price, but you can see a list of the orders put in if you log on an actual exchange like Bittrex. When I saw the sell and buy orders sitting in a queue waiting to be filled, some low-ball, etc., things starting to click for me.

The above is what I've gleaned from observation and reading. I could be wrong - and if there's one thing about this crypto bubble craze, is it's motivated me to learn about markets/exchanges, money, cryptography, and more. And to think about this things more abstractly and even critically.

Why does this question have so many upvotes?