PWS
Pacer WealthShield ETF
stock BATS ETF

I have a Fidelity Cash Management Account with Cash Manager linked to a margin account. That means, to my understanding, that a debit larger than the current balance available to withdraw will (usually) be accepted and draw from available margin instead.
What I'm not quite sure about is when this settles, so to speak. Let's say I sell $100 of securities on a Monday, and a same-day ACH debit transaction of $100 is initiated against the account on that same Monday. Will the ACH transaction cause margin to accrue before the securities settle on early Tuesday, or do they get processed at the same time and thereby avoid margin entirely?
---
The main reason I'm unsure about this is the following [FAQ](https://www.fidelity.com/spend-save/faqs-cash-management-account) entry:
> **Can the personal withdrawal service (PWS) be a Fidelity® Cash Management Account feature, and can it be used in conjunction with the Cash Manager feature?**
>
> Yes, during the overnight processing cycle for money movement associated with a Fidelity account, automatic investment (AI) is generally processed first, followed by PWS second, and Cash Manager third. This means that if a Fidelity® Cash Management Account or a Cash Manager funding account has a mix of the above money movement features enabled, funds will be moved based on the processing priority outlined above. Any money movement transaction which impacts the account’s core cash balance (for example: purchase, wire check redemption, IRA contribution) may affect PWS, AI, or Cash Manager money movement.
This implies that neither Cash Manager nor debits in general actually take action until that processing cycle, which is presumably also when settlement occurs.
---
What I ultimately want, by the way, is to keep my funds invested as long as possible, with margin available as a fallback in case of a liquidity crisis or similar black swan event.

I have a Fidelity Cash Management Account with Cash Manager linked to a margin account. That means, to my understanding, that a debit larger than the current balance available to withdraw will (usually) be accepted and draw from available margin instead.
What I'm not quite sure about is when this settles, so to speak. Let's say I sell $100 of securities on a Monday, and a same-day ACH debit transaction of $100 is initiated against the account on that same Monday. Will the ACH transaction cause margin to accrue before the securities settle on early Tuesday, or do they get processed at the same time and thereby avoid margin entirely?
---
The main reason I'm unsure about this is the following [FAQ](https://www.fidelity.com/spend-save/faqs-cash-management-account) entry:
> **Can the personal withdrawal service (PWS) be a Fidelity® Cash Management Account feature, and can it be used in conjunction with the Cash Manager feature?**
>
> Yes, during the overnight processing cycle for money movement associated with a Fidelity account, automatic investment (AI) is generally processed first, followed by PWS second, and Cash Manager third. This means that if a Fidelity® Cash Management Account or a Cash Manager funding account has a mix of the above money movement features enabled, funds will be moved based on the processing priority outlined above. Any money movement transaction which impacts the account’s core cash balance (for example: purchase, wire check redemption, IRA contribution) may affect PWS, AI, or Cash Manager money movement.
This implies that neither Cash Manager nor debits in general actually take action until that processing cycle, which is presumably also when settlement occurs.
---
What I ultimately want, by the way, is to keep my funds invested as long as possible, with margin available as a fallback in case of a liquidity crisis or similar black swan event.