The resurgence of Rafael Nadal and Roger Federer this season is all about turning a liability into an asset.
If tennis were investing, these two would be the master traders of 2017, the best on tour at taking a losing stock and turning it into a winning one.
The stock in focus is second serves.
Second serves are generally underrated, underperforming and under the radar when it comes to the discussion of tennis greats. Second serves for most of the tennis market are a speculative stock, but not for Nadal and Federer.