Nature of risk
A drawdown is the decline from an asset's peak to its subsequent bottom, and it is a true test of both the portfolio and investor psychology.
Foundational risk management is not intended to eliminate all possibility of loss. That is impossible in investing. The goal is to identify potential avenues for significant losses, limit the scale of losses, and keep investors in a position to continue when the market goes against expectations.
Analytical framework
The deeper the drawdown, the greater the gain needed to recover. A 20 percent loss requires a 25 percent gain to break even; a 50 percent loss requires a 100 percent gain. Drawdown management is not intended to avoid all losses, but rather to keep losses within a recoverable range and not force you to sell at the bottom.
A risk needs to be evaluated through three layers: probability of occurrence, severity of damage if it occurs, and ability to recover afterward. Many investors only focus on probability, for example 'this probability is low', but ignore that if it happens the consequences can break the entire plan.
Code of practice
Before investing, determine the maximum drawdown you can bear and take specific actions if your portfolio hits that threshold.
Risk rules should be written into specific actions: weight limits, leverage limits, minimum cash levels, rebalancing thresholds, selling conditions or review schedules. If the rule cannot be measured, it is easy to ignore when emotions run high.
Mistakes to avoid
Looking only at the average return without asking whether the drawdown is bearable.
Great risks often accumulate when everything seems favorable. When short-term returns are good, it is easy for investors to increase positions, reduce cash or ignore conflicting data. Stress-test risk most carefully after a winning period, not just after a loss.