IBOR and Accounting NAV Divergence Intraday
A multi-asset portfolio with £850m NAV shows investment book cash £2.1m higher than the accounting book at 14:00 on a trade date. The difference relates to a £25m sterling corporate bond purchase with £410k accrued interest, an FX forward collateral call, and a custodian cash feed that lags by two hours. The investment book records trades on trade date and forecasts settlement; the accounting book posts at custodian-confirmed settlement. The portfolio manager wants to use the investment book cash figure to fund a £30m client subscription due tomorrow. Operations says the accounting NAV is authoritative for client reporting and valuation. The reconciliation team has one open break from yesterday and no intraday automated match. Month-end is in three days. The CIO asks which book should drive the subscription decision and what controls are needed.
1. Explain why the two books diverge and whether either figure is wrong.
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Neither figure is necessarily wrong; they answer different questions. The investment book is an investment-consensus view that records the bond purchase on trade date and forecasts the cash needed at settlement. The accounting book reflects custodian-confirmed settlement and accounting entries, so it may not yet include the trade-date commitment or the accrued interest treatment. The £2.1m gap is consistent with a £25m bond purchase, £410k accrued interest, an FX collateral call, and a two-hour custodian feed lag, although the exact arithmetic must be reconciled line by line.
The key distinction is trade-date versus settlement-date perspective and forecast versus confirmed cash. The accounting NAV is authoritative for official valuation and client reporting because it is governed, reconciled and used for NAV production. The investment book is authoritative for investment decisions and forward cash projections, provided its settlement forecasts are reliable. Calling one 'wrong' misses the control issue: the firm is using an unconfirmed intraday projection as if it were available cash.
2. Which book should drive the £30m subscription decision, and what would you recommend to the CIO?
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The subscription should be funded from confirmed or readily available cash, not from the investment book's forecast alone. I would use the accounting book and custodian available-cash position as the base, then add only confirmed receivables and subtract committed settlements. The investment book can inform the forecast, but the £2.1m difference must be explained and the FX collateral call must be treated as a committed outflow unless confirmed otherwise.
The recommendation to the CIO is to approve the subscription only after operations produces a cash ladder showing opening confirmed cash, confirmed inflows, committed outflows, the bond settlement and the collateral call. If the available buffer is below the firm's minimum, the firm should arrange short-term funding or delay the subscription rather than rely on the higher IBOR figure. The reasoning is that a subscription is a real cash obligation, and an intraday forecast error would create a settlement fail or an unintended overdraft.
3. What intraday reconciliation and governance controls should be introduced?
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Introduce an automated intraday cash reconciliation between the investment book, accounting book and custodian, with tolerance thresholds by currency and portfolio. The reconciliation should distinguish timing differences, accrued interest, unsettled trades and collateral movements, so operators do not treat every gap as a break. Add a cash ladder that is signed off before any large subscription or redemption decision, and require a two-hour feed-lag indicator on the dashboard.
Governance should assign ownership of the investment book and accounting book to separate functions with a documented reconciliation protocol, not a single informal owner. The open break from yesterday should be aged and escalated. Month-end should include a formal sign-off that all material intraday differences are explained. The reasoning is that the books serve different purposes, so the control is not to force them to match every minute; it is to make the differences transparent, owned and bounded before cash decisions are taken.