I looked at the site; interesting. It looks like a very typical martingale algorithm with the characteristic step performance. But the histories are quite short (the longest are a couple thousand trades from what I could see). The incremental profit is also quite high on these which (as I wrote about in the article) can mean the risk of collapse is higher – assuming it is a classic Martingale. With regard to the black swan events you mentioned. You don’t even need one of these to push some systems over. Depending on the leverage, just a drawdown of a few percent can be enough to tip them over.