To everyone asking for more detail - don't bother. I don't mean to sound mean, OP, but if you have alpha ("several basic Buffett-style value strategies seem to

To everyone asking for more detail - don't bother. I don't mean to sound mean, OP, but if you have alpha ("several basic Buffett-style value strategies seem to beat the S&P 500 handily"), go start a prop shop and make millions of dollars. You can turn huge profits with even miniscule alpha. The problem is, armchair traders typically commit a few classical blunders: 1. Accidentally used future information to make trading decisions in backtesting. Obviously a crystal ball would make for GREAT alpha. And while you might think it's easy to avoid doing this, there can be some very subtle oopsies that are not apparent at all to even a somewhat sophisticated analyst that will catch you out. This was a common oopsie I would see our analysts do, sometimes only even becoming evident after the research team had vetted and idea and they hand it off to me to implement and I'd be sitting there in the data flow and have to tell them "yeah this data item you used, it's latency sensitive, did you make sure you were using the appropriate network path when you keyed into the dict or did you just hardcode the common one - because if you hardcoded then you're using a crystal ball for all the other network paths". 2. Assuming that if you see a price, you can trade at that price. Even HFTs can't just go get any ole' price they see. 2.5. A tangent to 2 is that your own trading activity can impact prices. Not important if your alpha is long term but if it's short term then this can be significant. 3. Ignored trading fees, and I don't mean brokerage fees - I mean SEC fees, etc that are usually very small for most retail trades so most brokerages don't even show you them (especially because depending on exactly how they executed your trade they might be different than you'd get if you just sent them to an exchange). 4. Not taking into account tail risks. Look at how many retail investors got blown the fuck up when XIV died [0] [0] https://www.forbes.com/sites/jimcollins/2018/02/06/it-works-until-it-doesnt-work-the-death-of-xiv-shows-the-folly-of-gaming-market-volatility/?sh=15659ad43c38 https://www.forbes.com/sites/jimcollins/2018/02/06/it-works-... Trading is hard. There's literally armies of ridiculously sophisticated actors as your market participant peers. I always used to joke that the federal budget is to defense spending as our nation's brainpower is to finance. (We probably throw WAY too much %-wise at it, but damn do we get a world class product as a result.)