Billionaire currency trader George Soros has warned that a vote for Britain to leave European Union will trigger a plunge in the pound — without benefits that can come with a devalued currency.

In an op-ed piece in Tuesday's Guardian, Soros says a decision to leave the 28-nation bloc in Thursday's vote will cause sterling to drop quickly. Soros predicted the drop will be more dramatic than when Britain crashed out of the European Exchange Rate Mechanism in September 1992.

Soros substantially profited — at the expense of the Bank of England and the British government — when the pound lost 15 percent of its value.

Soros says those who believe a "leave" vote will have no impact on their personal finances are guilty of "wishful thinking."