12-1 momentum for beginners: what it means to buy the winners
Buy what has done well over the past year — with one strange-looking adjustment that turns out to be the whole idea.
Key takeaway
- Momentum means: what performed well over the past year tends, on average, to keep performing well for a while
- The most recent month is skipped because very recent jumps tend to reverse — the rule protects you from chasing
- It is a statistical tendency across many stocks, not a promise about any single one
The idea in plain words
Look at every stock in the market and ask one question: how has it done over the past year? Buy a basket of the best answers. Hold them for a few months, then ask the question again and refresh the basket. That is the entire system — no earnings analysis, no charts, no opinions about any company.
It works, to the extent it works, because trends in performance persist longer than they should. The stocks at the top of a one-year ranking have historically gone on to do better, on average, over the following months than the stocks at the bottom. This pattern has been found over and over, in market after market, for decades.
On average is doing heavy lifting in that sentence. Any single winner you buy can fall apart immediately. The claim is only about baskets, held for months, refreshed on schedule — which is why the system is always described in terms of lists rather than picks.
Why skip the most recent month?
Here is the strange-looking rule: when measuring that one-year performance, you stop counting a month ago. A stock's move over the last few weeks is deliberately ignored.
The reason is that very recent moves behave differently from year-long ones. A stock that jumped in the past few weeks tends, on average, to give part of that jump back — a snap-back effect. A stock that climbed steadily all year tends to keep climbing. If you rank on the full year including last month, your list fills up with recent jumpers about to snap back. Skipping the month removes them.
How it relates to dual momentum
If you have read about Dual Momentum (GEM), this will feel familiar. GEM asks 'which of these two markets did better over the past year?' and holds the winner. The 12-1 factor asks the same question about every stock at once and holds the top group. Same underlying idea — recent relative winners keep winning — applied at a much finer grain.
Dual momentum (GEM)
- Two index funds compared
- One holding at a time
- Has a built-in exit to bonds
- Fifteen minutes a month
12-1 factor
- Every stock ranked at once
- A basket of many names
- No natural exit — the ranking always has a top
- More data, more trades, more cost
The comparison also shows what the factor lacks: GEM's second step checks whether the winner is even beating cash, and steps aside if not. A pure ranking never steps aside. That is why the version here adds absolute conditions — and why, for most beginners, GEM is the better first momentum system and this one is what you graduate to.
What running it honestly feels like
- Most months are boring. You recompute a list, make a few swaps, and stop.
- You will constantly own things you have no view on. That is the design — the ranking has the view, you just execute it.
- There will be stretches where it lags the market for a long time, and the system gives you no signal to distinguish a resting edge from a dead one.
- Rarely, at big market turns, it can lose fast — the beaten-down stocks rally hardest off a bottom, and this system owns none of them at exactly that moment.
The trade being offered is clear once stated: a modest, well-documented average edge, in exchange for real costs, occasional sharp reversals, and the discipline to keep running a list through years when it looks broken. The people the factor has paid are the ones who kept computing it.
Common questions
- Is this just buying whatever is popular?
- It is close enough to that description that the skip-month rule matters. Popularity over the last few weeks is what the system deliberately excludes, because that is the part that reverses. Sustained outperformance over a year is what it buys — a related but measurably different thing.
- Do I need to short anything?
- No. The academic version shorts the year's losers as well, but the long side — owning the winners — is where the practical, retail-sized version of the strategy lives. Shorting adds borrow costs, unlimited-loss positions and most of the crash exposure.
- How is this different from trend following?
- A trend follower watches one chart and holds until its trend breaks. This system compares many stocks against each other and swaps on a calendar. The signals overlap — strong 12-1 names are usually in uptrends — but the bet is different: trend following bets a move continues; this bets the ranking's top group beats its bottom group on average.
The ideas behind it
This system assumes you already know these. Each one is explained from scratch in Investing 101.
These are documented methods described for study. Nothing here is investment advice, a recommendation, or a claim about future returns — every system on this page has losing periods, and the pages say where.
Reading about a system is not having one.
Plutux is where you write your own rules down, test them against real data, and keep the record your memory would otherwise rewrite. Join the waitlist for early access.