Depends on the way it unwinds. If it's through selling BTC to cover Tether redemptions, sure, that'd be bad for cryptocurrency prices. I have a feeling that it'll unwind like Mt. Gox, though - people who accepted Tethers or put deposits into Bitfinex wind up holding the bag when the fake money goes "poof".

You’re talking about two different markets. A Tether-USD is not the same as a USD. If anything, the fact that the irredeemable USDT even has value is a sign of the insanity playing out in the cryptocurrency market. A token worth 1 dollar but not really worth 1 dollar makes no sense at all.

that's about 0.6% of the market cap of bitcoin

"market cap" is a very bad representation of the overall value which is impossible to actually estimate. try selling 600 million worth of btc and see how that cap changes.

Dump large amounts of ANY asset and it will crash. It's only crypto that gets accused of having a "fake" market cap though.

It's only crypto that uses the term "market cap" to mean "outstanding crypto-tokens * price". That isn't what the term means in conventional finance. It's normally applied to shares.

5 BILLION dollars worth of bitcoins are sold every day. The trading volume is higher and the orderbooks are deeper than you think...

Google "Wash Trading"

Doesn't work in crypto markets. Taker fees are typically > 0.20%, with the notable exception of BitMex.

There is plenty of evidence of wash trading occurring on Bitfinex and other exchanges - there are also many accusations that the exchanges themselves wash trade, to pump up their own volumes. They don't need to pay their own fees!

Taker fees are 0.1-0.2% on Bitfinex. Wash trading would be too expensive.

Where is the evidence the exchange itself is doing it?

Those who are downvoting the parent, please explain why? He is correct. Is the assumption here that the exchanges themselves are wash trading and not charging themselves fees? Seems possible. But otherwise wash trading is very expensive due to the maker/taker fees.

Taker fees are significantly discounted for higher volume traders, because they bring smaller traders to an exchange. I know two mid-sized whales who have almost 0% rate as long as they trade certain number of BTC a month.

Korean exchanges are 0 fee.

Koreans account only for ~7% of the 5 billion USD/day.

Where are you getting this number from?

24h trading volume: https://coinmarketcap.com/currencies/bitcoin/#markets

This includes a lot of crypto-crypto volume. Just in the top ten, there's $168m Bitcoin Gold, $145m of Bitcoin Cash, $95m of something called "PowerLedger" that I'm hearing of now for the first time, and $84m of Neo.

Is this real trading activity, or is it people discovering that there's no feasible way to trade USD directly for the meme coin du jour?

You can't compare money and market cap directly. Millions of dollars can move the market cap by billions. It's because the books on exchanges are relatively thin.

Price is set by marginal transactions, not the amount of money converted over time.

And a whole lot of trust.