The Coppock Curve, a little-known stock market indicator, has just called the start of a new bull market.
While the name may not be familiar to most retail investors the Coppock Curve has, since being invented in the 1960s by a churchgoing economist, consistently signalled the start of a new bull market (apart from in 2001).
Technical analysts at Credit Suisse have run the calculations on the S&P 500 and noted that the curve has turned up, with the key chart point being 4,195.
This was noted by equity strategists at the investment bank, who also see other positive fundamental signals in US macroeconomic data that could imply the Federal Reserve could soon be able to pivot on interest rates, including lower wage growth and earnings revisions becoming less negative.
But caution still seemed to be the overidding theme, with recession risks "flashing bright red" and the strategists noting that "since 1960, the market has always troughed after a recession started", on average at 11 months.
That brings us back to Coppock, as the period of 11 months is a key part of his calculation of how to time the bottom of the market.
As a behavioural economist who was also a devout Episcopalian, Edwin Coppock was asked by his church to come up with a reliable way of timing investments in the stock market and based his calculations on the length of time it takes to get over a bereavement, which he saw as psychologically equivalent to a big investment loss.
The Coppock's many adherents say it is infallible in flagging up the big market swings, though its signals sometimes point to blips in a continuing bull or bear market.