No Hard Rules at Selection. Discipline at Execution. The Filter in Practice

There is no universally correct method. No asset class that is always the answer. No allocation that works for every investor in every regime. That is the “no hard rules” claim. It lives at the selection layer.

Once a method has been chosen because it matches the four levers and the current conditions, the rules of that method are followed. Pre-defined risk. Pre-defined exits. Scheduled reviews. Honest updates when the thesis changes. No renegotiation under pressure. That is the discipline claim. It lives at the execution layer.

The two do not conflict. They operate on different decisions. Flexibility about the menu. Discipline about the meal.

Where people invert them

The common failure is using “there are no hard rules” as permission to skip the work inside the chosen method. “There are no hard rules about when to sell” is wrong. The method dictates the sell condition. You wrote it before you entered. “There are no hard rules about position sizing” is wrong. The size is a function of the edge and the portfolio risk budget. “There are no hard rules about risk management” is the most expensive version. Risk rules are non-negotiable across every method.

The opposite error is treating a method choice as permanent dogma. Levers move. Regimes shift. A method that fitted in accumulation can become a mismatch in drawdown. Switching is allowed. The signal for switching is a change in the levers or a sustained failure of the method’s assumptions, not a bad week or a better-looking story somewhere else.

The six-question filter

Run these over any rule you are tempted to break or any passage that sounds like licence to drift.

Am I attacking method dogma or execution discipline? If the first, the pushback is on-brand. If the second, rewrite or cut.

Does this tell the reader they get to choose, or that they get to wing it? Choosing is the point. Winging it is the failure mode.

If applied to the next trade, does the process get tighter or looser? Tighter is correct.

Is “no hard rules” being used to dismiss something the reader still has to do? If yes, the conflict is present. The rules differ by method. You still must have them, written, and followed.

Could a dogmatist quote this to justify never updating? If yes, revise.

Could a lazy investor quote this to justify never writing a thesis or defining risk? If yes, cut it.

Applied examples

Value investing has no hard rule that says you must own low price-to-book stocks. It does have a hard rule that you estimate intrinsic value, leave a margin for error, and exit or review when the business thesis breaks. The first is selection. The second is execution.

Momentum has no hard rule that says you must own the highest-flying names forever. It does have a hard rule that you sell when leadership or the fundamental acceleration ends. Holding through the break because “there are no hard rules” is how gains are given back.

Passive has no hard rule that says the equity weight must be 100 percent until age 60. It does have a hard rule that you rebalance to the written allocation and that you have a drawdown plan before withdrawals begin. Ignoring the second because markets “always recover” is the mismatch that sequence risk punishes.

What to do with this

Take the method you currently use most. Write the three rules that are non-negotiable for that method (entry condition or allocation, invalidation or rebalance trigger, review cadence). If you cannot write them, you do not yet have a method. You have a preference. Preferences get renegotiated at the worst moment. Written rules do not.