Idle cash earns Treasury bills

What it does

Each evening, code holds the cash your book is not using in a short-term Treasury-bill fund (SGOV) instead of leaving it idle

What it never does

Borrow, skip a limit or crowd out a buy: the fund is sold first whenever a buy needs its cash or its room

State today

Decided and built, switched off in this build: every book keeps idle cash as cash until the setting ships

Who trades it

Code, as part of the core sleeve; the PM never picks it and never sells it

This feature is decided and its machinery is in this build, switched off: nothing about your book changes until the setting that turns it on, and the row that shows it, ship together in a later release. This page describes what it will do.

What counts as idle cash

Your cash, minus every buy that is already on its way (orders working at the broker, orders waiting in your Inbox, and the buys the desk wrote in the same session), minus what the core sleeve itself still needs to buy, minus a reserve. The reserve is the largest single order your book can place (your per-order limit on Risk › Limits) and never less than 2% of the book, so the desk can always write its next ticket without waiting for a sale. What is left is idle, and idle cash is swept into the fund at the next open like any other core order: it appears in the Inbox as a core holding, waits for you if it is above your approval line, and passes every risk check on the way.

Inside every limit, and never in the desk's way

The Treasury-bill fund is a position like any other to the Executor, so the sweep can only use the room your limits leave: at most your largest-position limit in the fund, at most one per-order limit per day, and never the part of your total-invested limit that the reserve keeps free, nor the part a buy already on its way will take. Whatever a limit keeps out stays as cash, and the evening plan says how much and which limit did it. The desk, for its part, reads the fund as cash: its exposure line and its order preview count the book as if the fund were already sold, because code sells it first whenever a buy needs the room (next section). The cash floor your posture keeps out of the market (40% on Moderate) stays cash: letting a Treasury-bill fund count as cash for the invested limits themselves is a separate decision that has not been made.

Sold first when a buy needs its cash or its room

Two things can make a buy fail at the open: not enough cash, or not enough room under your total-invested limit. The fund is sold ahead of the buy in either case. Whenever the buys already committed would leave less than half the reserve free, in cash or in room under the limit, code sells enough of the fund to fund them and to restore the reserve, and that sale is queued ahead of the buys so it goes out first; the buys follow two minutes later. This happens in the evening pass for orders parked overnight and in any daytime session whose buys need it. The Executor still checks every buy against your actual cash and limits (it never uses margin): a buy that does not fit is refused exactly as it always was.

Only on a margin-type account

On a cash account, the money from a sale is not available until the next day, so a fund sold this morning could not pay for a buy this morning. Books whose broker reports a cash account (most accounts under $2,000) therefore keep idle cash as cash, and the setting says so. Nothing about this uses margin: the account type only decides whether a same-day sale settles in time.

Keeping it as cash instead

Once the setting ships, choosing keep as cash is one click and takes effect at the next evening pass: nothing new is bought, and a Treasury-bill lot the sweep bought on a posture whose core has no Treasury-bill part of its own (Moderate, Aggressive, Speculative) is sold back to cash. Turning the sweep back on asks for your authenticator code, because it puts money back into the market, however cash-like. Both are recorded in Activity like every other setting change.