This, however, may be a problem for the broader market because according to research from Smart Insider, the market is now the most overbought since the first dotcom bubble, as "executives across the US are shedding stock in their own companies at the fastest pace in two decades, amid concerns that the long bull market in equities is reaching its final stages."

As the FT reports, corporate insiders - typically CEOs, CFOs, and board members, but also venture capital and other early state investors - sold a combined $19BN of stock in their companies through to mid-September. Annualized, this puts them on track to hit $26BN for the year, which would mark the most active year since 2000, when executives sold $37bn of stock amid the giddy highs of the dotcom bubble. That 2019 total would also set a post-crisis high, eclipsing the $25bn of stock sold in 2017.