Size & Manage the Trade

You've found a Grade A setup — the regime backs it, the signal's live. Now the question that separates amateurs from professionals: how much do you buy, and what do you do once you're in? Finding the trade is the easy part — any screener spits out stocks in uptrends. The skill is managing the position from entry to exit, and it's where most people quietly lose.

Size to your conviction#

The grade tells you how much to bet. That's the whole rule. Grade A gets your biggest size; B moderate; C small; D for experienced hands only. For most people, full size is something like 5–10% of the account — packaging is personal — but the shape matters more than the number: your A's are meaningfully bigger than your B's, which are bigger than your C's. Do that and your portfolio tilts itself toward your best ideas automatically. Your profits come from a few big A's that run; your losses stay small because the low-conviction trades were small and cut fast.

The one number to tattoo on your forearm: 1–2%#

That's the most you ever risk on a single trade. Lose it all and you're down 1–2% — painful, survivable, fight another day. On a Grade A you run no stop or a wide one, so you control risk through size: the position is small enough that even an ugly move costs no more than that 1–2%. On a B or C with a hard stop, the maths is simple — stop 3% below entry, want to risk 1%? Your position is about a third of the account (1 ÷ 3 = 33%). The arithmetic forces small bets on weak setups and big bets on strong ones. Exactly right.

Build in increments#

Don't go all-in on day one. Almost every new trader buys the full position in one shot, watches it dip 2% the next day — a totally normal pullback — and now they're underwater with no ammunition left to add. Instead, build in: take 40–50% on day one, add as the trade confirms and the grade holds. Better average price, each add is extra confirmation, and you're never fully exposed on the day you know the least. Like a poker player with a strong hand — you don't shove all-in and scare everyone off; you build the pot as the cards prove your read.

Why protection is everything#

Lose 50% and you don't need 50% back — you need 100%. You have to double what's left just to break even. Lose 80% and you need 400%; lose 90% and you need 900% — a fantasy. Dig a deep hole and the maths makes it nearly impossible to climb out. That's why your first question on every trade is never "how much can I make?" — it's "how much can I lose?" Every blown-up account in history started with "one more day": bought at 200, "one more day" at 190, at 178, at 165, finally sold at 115 — a 42% loss that needs a 72% gain to undo. The market doesn't know your entry price and doesn't care. Respond to reality; don't hope for a different one.

Never short#

A rule that cuts against everything you'll hear in the forums: don't short. The market rises in roughly two years out of three — short it and the odds are against you most of the time. Fortunes get made shorting crashes, sure; for every one of those, hundreds shorted in 2006, 2007, early 2008 and got wiped out before the crash arrived. Here's how it really goes: you short an "overvalued" stock at 150, it runs to 160, 175, 200, you're down 33% facing a margin call, you cover at 195 — and three months later it's at 170, still above your entry. You were right and still lost a fortune. Always be long. If something's going down, don't trade it — move to the next thing going up. There's always something going up somewhere.

Managing the trade: do nothing, well#

Once you're in, the hard skill is doing nothing well. Most trades start boring — and boring is a feature: no drama, no emotional decisions. The best traders accept the full risk before they enter; they've already made peace with the worst case, which frees them from sweating the quiet middle. If you're anxious through the boring days, you probably never truly accepted the risk. Set your orders and walk away. The research is blunt: the fiddlers — nudging stops, banking profit too early, adding at the wrong time — underperform the ones who sit still.

Trimming. When the trade works and hits your exit, don't dump it all — trim. Sell 30–50%, bank a real gain, let the rest run, because a Grade A that's still trending tends to continue. The trim locks in money that's now actually yours and turns the rest into "house money," so you hold through the next dip without flinching. The mirror is the trader who won't trim: in 2019 one rode a stock from 85 to 132, ignored the exit signal at 125 and again at 130 — "it's going to 150" — watched it fall back to 108, and finally sold at 110, leaving £8,000 on the table. It did hit 150 — six months later, long after he'd gone.

The three exits — and only three. One: the grade drops below A — the macro support that justified holding is gone, so you go too. Two: the trend breaks — higher highs and lows become lower highs and lows; the price is telling you the money flow reversed. Three: a real event changes the picture — an earnings disaster, a regime-shifting shock; you don't wait for tomorrow's signal, you're out at the open. What's not on the list: "I got bored," "I read a bearish article," "it hasn't moved in three days." Exits are driven by data, not feelings.

When it gets scary#

A stock gaps down 12% on bad earnings and gets downgraded — you sell at the open, no "wait for the bounce." Extreme moves cluster: the first gap is rarely the worst, so cut it at 12% rather than ride it to 30%. Sized right, that costs you 1–2% of the account — which is the whole point of sizing. And the market-wide selloff: the whole market drops, your phone's buzzing, everything feels apocalyptic. Before you touch anything, ask two questions — has the regime changed? has the grade changed? In August 2024 the market fell over 5% in three days on recession fear and a yen carry-trade unwind. But growth was still expanding, inflation still cooling — the regime hadn't changed; it was a positioning unwind, not a collapse. Three weeks later the market made new highs. The red number is designed to scare you. The regime is designed to protect you.

Twelve days, start to finish#

Put it together. Regime 1, a chip stock in a clean uptrend, Grade A: entry 142, exit 151.50. Day 1 you take 40% at 142. Day 3 it drops to 141 on a sector selloff — headlines screaming "semiconductor selloff accelerates," your mate texting you — but the grade's still A, the regime's still 1, the weekly trend's still up. You add. That's the moment the trade is won or lost, and you hold. Day 4, dead quiet, you finish building. Then it moves: by Day 6 you're up over £2,000 and every instinct says "lock it in" — the system says hold, so you hold. Day 10 you trim into strength at 156.80; Day 12 the rest fills at 160. Nearly £7,000 over twelve days, fifteen minutes a morning. Without a system, every one of those ten decision points was a chance to get it wrong. The system made nine of them for you. All you did was listen.

Keep a journal#

Log every trade: the setup, how you managed it, the result, and any deviation and what you were feeling. (Judging a trade by its outcome instead of its process — "resulting" — is the trap; more on that in the psychology chapter.) Review every 20–30 trades and the patterns jump out — one trader found she bailed 2–3 days early every time, leaving 40% of the move behind; she fixed it and her returns doubled. Five minutes a trade. Highest-return habit there is.