Momentum investing that runs itself.
Once a month, ARX Momentum ranks a fixed list of large, liquid stocks and ETFs by momentum, then rebalances your own Trading 212 account for you. Your money never leaves your account.
- No custody of your money
- Pause any time
- £29 a month, flat
Set it up once. It handles every month after.
- 01
Connect Trading 212
Create an API key in the Trading 212 app. We walk you through it, step by step, in about two minutes.
- 02
Switch on automatic
Choose automatic trading. You can pause it at any time, or approve each trade yourself instead.
- 03
It rebalances monthly
On the 2nd trading day of each month, Momentum sells what has dropped out of the ranking and buys the leaders.
- 04
See everything
Your dashboard shows your holdings, every trade and why it happened. Trading 212 shows the same trades.
Real trades, published every month.
Momentum’s live record began with the October 2026 rebalance. After each monthly rebalance we publish the founder account’s result here, next to the S&P 500 in pounds, good months and bad.
We don’t show back-tested returns. Simulations can make any strategy look brilliant in hindsight, so we’d rather show you what really happens.
October rebalance
Monday 5 October 2026 · founder account- SOLDPalo Alto Networkswhole holding
- SOLDAMDtrimmed
- SOLDMicron Technologytrimmed
- BOUGHTMarathon Petroleumnew
- BOUGHTFreeport-McMoRannew
If anything looks wrong, it stops. It never guesses.
Automation is only worth having if you can trust it with your money. Every rebalance passes the same checks, and any failure pauses trading rather than pushing on.
Sales confirmed before buying
Nothing is bought until Trading 212 confirms every sale has filled. If a sale fails, nothing is bought and the problem is flagged.
Never spends cash you don't have
Buys are sized from your real cash once the sales have landed, with a safety margin kept back.
No leftover fractions
When a stock leaves the portfolio, Momentum sells the whole holding rather than leaving tiny fractions behind.
One switch to pause
Pause automatic trading from your dashboard whenever you like. Your holdings stay exactly where they are.
Checked before every run
Fresh account data, prices and exchange rates are checked before each rebalance. If anything is stale, it doesn't trade.
One flat fee. Never a percentage of your money.
The price is the same whether you invest £1,000 or £100,000. Trading 212’s own charges, such as currency conversion on US shares, still apply.
- Monthly rebalancing, fully automatic
- Dashboard with every trade explained
- Works with Stocks ISA and Invest accounts
- Cancel any time
Who holds my money?
Trading 212 does, in your own account. ARX never holds, moves or withdraws your money. The API key you create lets Momentum place trades, nothing else.
Can I stop it?
Yes. Pause from your dashboard, or delete the API key in Trading 212 and Momentum can no longer trade at all.
What happens if a trade fails?
The rebalance stops safely. Nothing is bought until every sale is confirmed, and the problem is flagged for review.
Does it work with a Stocks ISA?
Yes, with Trading 212 Stocks ISA and Invest accounts.
How much do I need to start?
Momentum doesn't set a minimum, but very small accounts are harder to split sensibly across several holdings.
Is this financial advice?
No. Momentum is software that follows a fixed set of rules. It doesn't know your circumstances, so you decide whether it suits you.
Let the rules do the work.
Set up in about ten minutes. Your first rebalance runs on the next 2nd trading day.
Start automating