The tech-heavy Nasdaq 100 index has soared almost 40 per cent over the last year, prompting various critics to complain of seemingly extraordinary gains driven by central banks’ easy money policies.

That's not the case, says Price Action Lab blogger Michael Harris. Yes, a 38 per cent 12-month gain is high, but it's far from "extraordinary". Rather, it's less than one standard deviation above the one-year norm, notes Harris, who examined Nasdaq data dating back to 1985.

Freakish

Indeed, one-year returns have been much higher in the past, particularly during the 1990s. There have been 11 occasions where one-year Nasdaq returns exceeded 50 per cent and six occasions where they topped 80 per cent.

Commentators often assume there’s something freakish about big returns, but wild swings are a feature of the markets, not a bug. “If the Fed is driving the markets as many analysts claim,” says Harris, “it hasn’t been doing a good job judging from the market growth in the 90s”.