I'm a big fan of yours but I don't believe the study about gaps always filling 19% of the time. I believe the number is accurate, but not because the gap needs to fill. random walks will fill them most of the time. Also it's not useful if you don't put a time limit on it. In 100 years 91.4% of all gaps fill? In 3 weeks 91.4% of gaps fill?

Of course the island could happen and these could still fill at a much later date.

Also, how can you really be sure it's a gap if it's trading around the world, and it only really gaps in our 9-4:30 workday? Like FXE.

Fun fact - there is a gap in ripple somehow, despite the fact that it never rests. Don't worry though, it's been filled!