What the Acubic Capital Figure Controls

Key takeaways

• The capital figure defines the managed scope: Acubic reads and trades only within the amount you specify at connection time.
• Every order quantity scales directly from it: target weight multiplied by the capital figure, divided by the current share price, rounded down to the nearest whole share.
• Holdings outside the capital boundary are left untouched on every rebalance, regardless of automation mode or which broker you use.
• Adding money to your account does not automatically expand the managed scope; you update the figure to include it.
• The figure works the same way on eToro and Trading 212, but the account structure it sits inside differs between the two brokers.

When you connect a broker account to Acubic, the final setup step asks you to enter one number: how much of your account Acubic should work with. That number is the capital figure. It appears in the connection guide, the automation modes article, and the position sizing logic, usually described in one sentence: positions outside the managed set are left alone. This article explains what that means in practice, what the capital figure controls on each rebalance, and what it cannot do.

What the capital figure is

The capital figure is the boundary of Acubic's authority over your account. It is the amount you authorise the tool to work with; everything else in the account, whether existing positions, cash you are holding in reserve, or holdings you want to manage yourself, stays outside that boundary.

Setting it to 5,000 on a 10,000 account means Acubic calculates and places orders as if it has 5,000 to work with. The other 5,000 is not read as part of the rebalance calculation, and no orders are placed against it. This holds even if the market value of the managed positions no longer matches the capital figure exactly: the figure is the reference point for the calculation, not a live cash balance.

Acubic does not move money between accounts or between portions of an account. The capital figure is not a transfer instruction. It is the number the scheduler uses when it converts target weights into share quantities.

What it controls: order quantities

On every rebalance, the scheduler converts each holding's target weight into a share quantity. The capital figure is what makes that conversion possible.

The calculation runs as follows: take the target weight for a position, multiply it by the capital figure to get the intended position value, then divide by the current share price to get a share count. That count is almost always a non-integer. The scheduler rounds down to the nearest whole number. A calculated count of 6.9 becomes 6; a count of 0.7 becomes 0, meaning no order is placed for that position on that run.

Capital figure	Target weight	Share price	Calculated count	Order placed
5,000	8%	40	10.0	10 shares
5,000	8%	43	9.3	9 shares
10,000	8%	40	20.0	20 shares
10,000	8%	43	18.6	18 shares

Rounding down rather than up is a deliberate conservative choice: Acubic buys slightly less than the full calculated target rather than slightly more. This keeps total outlay within the capital figure and avoids overshooting any position's allocation. The full mechanics, including the rounding rule and the drift threshold, are explained in how position sizing works in Acubic.

The practical implication is direct. If a rebalance order looks smaller than you expected and the target weights look correct, the most likely explanation is that the capital figure is set lower than the total amount you intended Acubic to work with. Increasing the figure scales every subsequent order proportionally. No strategy setting controls absolute order size; strategy settings only control weights. Absolute size is entirely a function of the capital figure.

What stays outside the managed scope

Everything outside the capital figure is excluded from every rebalance calculation, with no exceptions. That exclusion covers several situations new users regularly ask about.

Positions you held before connecting remain where they are. If you connected with a capital figure of 5,000 and already held other investments in the same account, those holdings are not touched. Acubic does not sell them to free up capital for the managed set, and it does not include their value when calculating order quantities.

Cash added to your account after the connection is set up sits outside the managed scope unless you update the capital figure to include it. The scheduler calculates against the figure you set, not against your current account value. If you deposit additional funds and want them included, you change the figure to reflect the new total. The next rebalance uses the updated number.

On eToro, positions managed by eToro's own tools fall outside the capital boundary. Positions you are copy trading, and allocations inside eToro Smart Portfolios, are excluded from the managed set; Acubic filters out positions with a copy relationship, so they never appear in the order set. For a comparison of what Smart Portfolios provide versus what a risk-profiled portfolio built from your inputs provides, see eToro Smart Portfolios vs a portfolio built for you.

How the figure differs by broker

The capital figure works identically on both eToro and Trading 212 at the calculation level. What differs is the account structure it sits inside.

On Trading 212, your API key covers the whole Invest or Stocks ISA account. The capital figure is the boundary Acubic operates within on that account. All three automation modes, Manual, one-click approval, and full automatic, are available directly on the main account. The capital figure does not change which modes are available; it determines only the scope of trades within whichever mode you choose.

On a standard eToro connection, the capital figure defines the managed scope within your main eToro account, and a standard connection runs on one-click approval only: each prepared rebalance waits for your approval before any order reaches the broker. No setting inside Acubic changes this for a main-account eToro connection.

Unattended rebalancing on eToro is available only on an eToro sub-account: a separately funded account inside eToro where Acubic places the strategy's trades, sized to the amount you fund it with. eToro's own menu for this feature calls it Agent Portfolios. The capital figure on an eToro sub-account corresponds to the amount you fund that sub-account with; order sizes scale to it in the same way as on any other connection.

For the full difference between what each broker allows, one-click vs full-auto rebalancing covers the broker constraints alongside the mode descriptions.

The sanity check

Before any order set reaches the broker, Acubic runs a check against the total calculated trade size relative to the capital figure. If the calculated order set is implausible relative to the managed value you set, the run halts and nothing is sent. The check catches a narrow class of problem: a stale position read or a price inconsistency that would produce orders wildly out of proportion to the amount in scope.

A portfolio in a normal state produces a small corrective order set on each scheduled date. An order set that looks structurally wrong relative to the capital figure is stopped rather than executed, and the halt is recorded in the audit log with a reason. No order in a halted run reaches the broker.

A broker rejection of a single order within an otherwise normal run is a different event. When the broker refuses one position, the remaining orders in that run continue independently. That behavior is distinct from a sanity-check halt, which stops the whole run before anything is sent.

Setting and updating the figure

The capital figure is set at connection time, as the final configuration step before the first rebalance runs. The connection guides walk through where this appears in the setup flow for each broker.

How to connect an eToro account to Acubic covers the eToro steps. How to connect a Trading 212 account to Acubic covers the Trading 212 equivalent.

The figure can be updated after the connection is live. Changes take effect on the next scheduled rebalance, not immediately. If you increase it today and the next rebalance fires tomorrow, tomorrow's calculation uses the new number. No rebalance triggers early because the figure changed.

Changing the capital figure does not change the strategy's target weights. It scales only the absolute quantities derived from them. A strategy that targets 8% in one holding and 12% in another keeps those weights regardless of what the capital figure is. What changes is whether those percentages translate to 4 shares or 8 shares.

What the capital figure does not do

Precision about limits is as useful as precision about capabilities.

It does not move money. Setting a capital figure of 5,000 does not transfer 5,000 anywhere. It tells the calculation how much to treat as the managed scope. The money stays in your broker account; Acubic places buy and sell orders within that scope as your broker executes them.

It does not lock up funds. Cash outside the capital figure remains in your account and is accessible to you. Acubic places no claim on it and places no restriction on what you do with it outside the managed set.

It does not prevent you from holding other positions alongside the managed set. Investments outside the boundary are entirely independent, and Acubic never touches positions outside it.

Acubic does not promise returns and cannot predict short-term market moves. The capital figure determines the scope of the managed set; what the market does within it determines outcomes. The AI portfolio builder is where you define a strategy and review the initial proposal before any broker connection is made.