One of my strategies has been treading water since the middle of 2009. I find the following scenarios plausible and list them in decresing order of my estimate of their plausibility: 1. a regime shift in the market makes this strategy unprofitable for now, it may recover at some undetermined point in the future. 2. a structural change in the market makes this strategy obsolete, it will never make any more money. 3. my broker (who happens to run an internal quant HF fund) reverse engineered this strategy and found a way to effectively front run my entries and take all the juice out. 4. other random people stumbled upon the inefficency this strategy was exploiting and found a faster or more efficient way to capture it, leaving no crumbs on the table for me. From a practical standpoint, what I did was to reduce the size of this strategy and keep monitoring it and deployed the resources towards other strategies that keep on working. I am particularly worried about scenario 3 above, and was contemplating obfuscating my remaining strategies. Do you guys think this paranoia is justified?