You have done your homework. You have read the news, studied the chart, and arrived at a clear view: today the market goes up, and you are positioned long. Then someone speaks. Maybe it is a trader you respect — someone with a bigger account, a longer track record, a reputation as better than you. And they say, with total confidence, the opposite: the market is going down. Short it.
What do you do? Everything in you wants to defer to the bigger reputation. Surely they know better. Surely you should flip your long to a short and follow the expert. Rule No. 9 says: no. Never. You trade your own forecast, or you trade nothing at all — and if their opinion has rattled you out of your own conviction, then the correct response is not to take their trade. It is to stand aside and do nothing.
You cannot hold a position you do not believe in
Start with the practical problem, because it is decisive on its own. Suppose you abandon your long and go short on the respected trader's say-so. You are now holding a position you do not actually believe in. And the moment that position moves against you — the moment the market ticks up, as your own analysis told you it would — you have nothing to hold onto.
When you trade your own forecast and the market goes against you, you have a thesis. You know why you are in the trade, you know the level at which you would be proven wrong, and you can hold through the noise with composure because the conviction is yours. But when you are in someone else's trade, you have none of that. You do not truly know their reasoning, their timeframe, their stop, or where they intend to take profit. You have inherited the position without the plan that makes it manageable. So when it wobbles, fear takes over instantly — and Rule No. 8 tells you exactly what happens to the frightened trader. You will panic out at the worst moment, because you were never standing on your own feet to begin with.
A borrowed conviction is not a conviction at all. It evaporates the instant it is tested, which is precisely when you need it most.
Even if they are right, it does not help you
Here is the part that surprises beginners. It does not even matter if the respected trader turns out to be correct. Trading their call still hurts you, for reasons that have nothing to do with this one outcome.
First, a better trader being right on average does not mean right this time. Rule No. 2 settled that: there is no hundred-percent chance, and the most respected voice in the room is wrong often enough to ruin anyone who follows blindly. You do not have access to their full context — what else they are positioned in, how this fits their larger book, what their real timeframe is. You are copying a single visible decision while missing everything around it that makes it sensible for them.
Second, and more importantly, a win you take on someone else's call teaches you nothing. You did not reason your way to it, so you cannot learn from it, and worse — it trains you to keep deferring. The next time you face a decision, you will reach for someone else's opinion again, because the last borrowed call worked. You are building dependence instead of skill. A trader who profits from following others has not become a better trader; he has become a better follower, and the day the voice he follows goes quiet or goes wrong, he has nothing of his own to fall back on.
This is the exact catastrophe of Rule No. 2 and Rule No. 4, where Jesse Livermore — one of the greatest traders who ever lived — was talked out of his own correct position by the respected Percy Thomas, and nearly destroyed himself. Livermore did not lose because Thomas was a fool. He lost because he abandoned his own forecast for someone else's, and a position you hold on borrowed conviction is a position you cannot defend when it turns. The lesson cost him a fortune. It is offered to you here for free.
Information is not the same as the decision
It is important to be precise about what this rule does not mean, because it is easy to misread it as "ignore everyone and everything." That is not it at all.
You absolutely should gather information. Rule No. 1 told you to read the news every morning; the path of a serious trader runs through books, through studying the great traders in works like Market Wizards, through watching the market and learning from everyone who has something real to teach. Information and education are the raw material of good judgement. The distinction is what you do with it. You take all of that input and you build your own forecast from it. The forecast is yours, the reasoning is yours, the decision is yours.
What Rule No. 9 forbids is outsourcing the live decision itself — letting another person's in-the-moment opinion override the conclusion you reached through your own work. There is a world of difference between learning a method from a great trader and letting a great trader make your call for you. The first builds you up. The second hollows you out. Gather everyone's information; take no one's decision.
When in doubt, do nothing
So what happens when the respected trader's contrary view genuinely shakes you? When you were confident in your long, and now, having heard a strong case for short, you simply do not know anymore?
The answer is the cleanest in all of trading: you do nothing. You close out, or you never enter, and you stand flat. Because notice the trap you are in — you no longer fully believe your own long, since it has been shaken, and you do not truly own the short, since it is not your analysis. You believe neither. To trade either from that muddled, uncertain state is to trade from exactly the confusion that Rule No. 8 warns will destroy you. The honest position, when your own conviction has been disturbed and not yet rebuilt, is no position at all. Flat is a position, and it is the right one whenever you are unsure. There is no shame and no cost in sitting out a move you do not understand. There is only cost in trading one you don't.
This is how you become a top trader
Felix puts the point sharply: you can only become a top trader by trading your own instinct. And this is the deepest reason for the rule, beyond any single trade. The skill of trading simply is the skill of forming your own judgement and acting on it — and then living with the consequences and learning from them. Every time you make your own call, right or wrong, you feed that learning loop: a win on your own reasoning confirms something real, and a loss on your own reasoning teaches you something you can actually use next time. That loop is how judgement is built, trade by trade, over the years it takes.
Every time you trade someone else's call instead, you skip the loop entirely. You learn nothing, you build nothing, and you stay dependent. A trader who only ever follows will never develop the instinct that defines a master, because instinct is not given — it is earned, through your own decisions and their outcomes. You cannot outsource the one thing that would make you great and expect to become great anyway.
The bottom line
Trade only your own forecast. When someone you respect — however much better they may be — tells you the opposite of what your own analysis says, do not flip to follow them, because a borrowed conviction collapses the moment it is tested, and even a winning borrowed call only deepens your dependence. Gather everyone's information, but make your own decision. And when your conviction has been genuinely shaken and you no longer know, do the cleanest thing there is: nothing.
Your account is yours. Your decisions must be too. That is not just how you protect yourself — it is the only way you ever become a trader worth following.