Every gold rush has its prospectors, and its sellers of maps to mines that do not exist. In 2017, anyone could create a token on Ethereum in an afternoon and sell it to the world in an initial coin offering, or ICO. Billions of dollars flowed in, often for little more than a whitepaper and a website.

By December 2017, bitcoin touched nearly $20,000. Some of the new projects became real and lasting. Many vanished. The regulators took notice: that summer, America's SEC had warned that many tokens sold this way were really securities, subject to the old rules.

After every great rush comes a long cold. Through 2018, bitcoin fell by more than 80% from its peak, and the ICO tokens fell further. The tourists went home. People called it crypto winter.

Winters return. In 2022, as prices fell again, lenders who had promised high yields — Celsius, Voyager, and the fund Three Arrows Capital — collapsed one after another, freezing their customers' savings. Yet in every winter, some builders stayed by the fire, and many of the tools people use today were built in the cold.

FTX, founded in 2019 by Sam Bankman-Fried, grew into one of the world's largest crypto exchanges, with its headquarters in the Bahamas, celebrity adverts, and its name on a basketball arena. It seemed untouchable.

In November 2022, a news report revealed that its sister firm, Alameda Research, was built largely on FTX's own token. Customers rushed to withdraw, and there was not enough money to pay them: their deposits had been secretly lent out. FTX filed for bankruptcy on 11 November. Bankman-Fried was convicted of fraud in 2023 and sentenced to 25 years in prison.

Where there is treasure, there are thieves. Hackers — many linked to North Korea's Lazarus Group — have stolen billions from exchanges and bridges. In February 2025, the exchange Bybit lost about $1.5 billion in ether in a single afternoon: the largest crypto theft ever recorded.

But a public notebook is a hard place to hide. Because every transfer is written down forever, investigators can trace stolen coins from address to address. In 2022, US agents recovered about 94,000 bitcoin stolen from the exchange Bitfinex six years earlier — footprints followed all the way home.

The tricks are old; only the costumes are new. Beware anyone who promises guaranteed returns, who tells you to hurry, or who asks for your seed phrase — no real helper ever will. Beware the rug pull, where a project's makers sell everything and vanish, and the friendly stranger online who, after weeks of kind messages, has one amazing investment to share.

The honest stall is quieter. Its code is open and audited; its team can be found; its returns come from somewhere you can explain. Before you buy, ask: who holds the keys, where does the money come from, and what happens if it fails? In crypto, as in any market square, the best protection is a curious and patient mind.