I write 50-page memos on single stocks. If you can't write 50 pages about why you own something, you shouldn't own it.
Trading isn't about being right on any single trade. It's about having a positive expected value across thousands of trades.
In cricket and in business, the result matters. But the process that gets you to the result matters more. Get the process right and the result takes care of itself.
A great idea with a bad process will fail every time. A great process will eventually find great ideas on its own.
Markets change. If your process does not change with them, you are managing yesterday's money.
Sell when the fundamental reasons you bought no longer exist, or when the price target is reached. Not before, not after.
Fashion week is my laboratory. Every runway is an experiment. That's where I find out what's next.
My work as an art conservator has many parallels with the type of thinking that goes into making investments.
A lot of people think they are okay because they use in-sample data for training and out-of-sample data for testing.
I hypothesized that there are patterns that work, and I would rather have the computer test trillions of patterns than just a few hundred that I had thought of.
Sometimes we give a little more weight to more recent data, but it is amazing how valuable older data still is.