Bitcoin reached a 17-month high on Tuesday amid rising speculation that US regulators will approve stock market funds that invest directly in cryptocurrency. The price increased more than 10 per cent to $34,872 a token, pulling back the losses seen in last year’s crash. The surge was driven by hopes that the Securities and Exchange Commission would approve an exchange-traded fund (ETF), abandoning its decade-long policy of refusing to approve spot ETFs. It followed a 10 per cent surge on Monday, when bitcoin posted its best day in nearly a year. An approval by the US SEC of an ETF that owns bi…