Kelly sizing is optimal long term, but is highly volatile. A common practice is to size by a fraction of Kelly, to reduce variance and since risk of ruin increases fast after 1.0 * Kelly. It also allows room for error in the probability predictions, to avoid going over 1.0 * Kelly by accident.
I try not to worry about stdev and focus on the soundness of my process, but in practice I have money split into higher-risk where I try to be clever, and low-risk failsafe investments to raise the floor of the worst case scenario.
I try not to worry about stdev and focus on the soundness of my process, but in practice I have money split into higher-risk where I try to be clever, and low-risk failsafe investments to raise the floor of the worst case scenario.