He qualified for the 2015 German Darts Masters and overcame Rowby-John Rodriguez 6–4, before losing 6–2 to Michael van Gerwen. Stone also reached the second round of the Dutch Darts Masters by beating Dean Winstanley 6–4 with an average of almost 100, but then narrowly lost 6–5 to Steve Beaton. His tour card expired at the end of 2015 and with Stone ranked 100th on the Order of Merit he needed to enter Q School. A single last 16 showing over the four days was not enough for Stone to win his place back. A trio of last 64 defeats saw him qualify for the 2016 UK Open, where he beat Johnny Haines 6–5, before losing 6–2 to Jamie Caven in the second round. Stone played in the majority of Challenge Tour events, with two last 16 defeats being his best runs.