Since 1950, the US market has registered 50 positive years out of 69 for a hit rate of 72 per cent. If we consider years when the market has risen in January, the likelihood of a positive return over the rest of the year jumps to 88 per cent.
Before anyone gets too excited, I should point out that this "January indicator" has been a little hit-and-miss lately. During the last 10 years, January and the rest of the year have moved in unison less half the time.
Last year is a good example. In January of 2018, US shares began the year with a hiss and a roar, rallying 5.6 per cent during the first month of trading.
That was the strongest start to a year since 1997, and it took the S&P 500 to 15 consecutive monthly rises (on a total return basis), equalling the record streak from 1958/59.
Despite the impressive start, US shares finished the year 6.2 per cent lower, the weakest return in a decade.
It's been comforting to see investor sentiment turn more positive during the last few weeks, but financial markets aren't out of the woods yet, and we probably haven't seen the end of last year's volatility.
It still pays to be a little cautious about some of the concerns that have emerged in recent months. This includes the path of economic growth, which has clearly slowed even if it doesn't yet point to recessionary conditions.
US interest rates will also be in focus, with the Federal Reserve projecting another two rate hikes in 2019, at odds with financial markets that believe there will be zero.
Trade tensions are still front of mind as the temporary truce between the US and China is set to expire soon, while Brexit developments will remain in the headlines as the official leaving date looms.
Closer to home, the February reporting season will gauge the health of corporate New Zealand, while potential changes to tax policy will be of interest to investors, as well as the broader business community.
Mark Lister is Head of Private Wealth Research at Craigs Investment Partners. This column is general in nature and should not be regarded as specific investment advice.