Research
Box Spread Financing vs. Pledged-Asset Lines
The 1-month Haven SPX Box Rate next to SOFR, the overnight index many pledged-asset lines use.
Key takeaway
From 2018 through 2025, the 1-month Haven SPX Box Rate averaged 0.39 percentage points above SOFR, the overnight index many pledged-asset lines use.
Navy line: 1-month Haven SPX Box Rate. Gray line: SOFR. This is the index comparison, not a history of lender spreads.
Yearly comparison
| Year | Days | 1-month Haven SPX Box Rate | SOFR | Haven minus SOFR, pp |
|---|---|---|---|---|
| 2018 | 165 | 2.45% | 1.97% | 0.47 |
| 2019 | 238 | 2.55% | 2.20% | 0.35 |
| 2020 | 231 | 0.93% | 0.37% | 0.56 |
| 2021 | 248 | 0.52% | 0.04% | 0.48 |
| 2022 | 244 | 2.11% | 1.64% | 0.47 |
| 2023 | 245 | 5.20% | 5.01% | 0.20 |
| 2024 | 237 | 5.44% | 5.14% | 0.30 |
| 2025 | 228 | 4.56% | 4.24% | 0.32 |
| 2026 | 170 | 4.08% | 3.65% | 0.43 |
The table starts in 2018, when SOFR begins. The cleaned 1-month Haven SPX Box Rate includes 2020 and 2021. 2026 runs through October 6. Pledged-asset spreads are set by the lender and are not in this table.
On 1,836 paired days from 2018 through 2025, the 1-month Haven SPX Box Rate averaged 2.98% and SOFR averaged 2.59%.
The gap was 0.56 percentage points in 2020 and 0.20 percentage points in 2023.
A March 16, 2026 description of Schwab's pledged-asset schedule put the add-on between 2.40 and 4.40 percentage points over SOFR, before an asset discount, when SOFR was 3.65%. Applied to the October 7 SOFR of 3.88%, that range is 6.28% to 8.28% before any discount. That is arithmetic on a dated description, not a rate checked on Schwab's site.
A pledged-asset line is a credit agreement. The Haven SPX Box Rate is not a line of credit.
Sources: Methodology · New York Fed SOFR · March 16, 2026 description of a Schwab PAL schedule. The table uses the cleaned daily history. The published daily CSV and JSON are separate files.
What this means
Many pledged-asset lines are priced as a spread over SOFR, so this chart is the index comparison, not a history of lender spreads. From 2018 through 2025 the 1-month Haven SPX Box Rate averaged 0.39 percentage points above SOFR before any add-on. A pledged-asset line is a credit agreement; the Haven SPX Box Rate is not a line of credit.
Haven Funding LLC is owned by Haven Systems LLC. Neither firm is a bank or a registered broker-dealer. Securities and execution services are provided through Interactive Brokers LLC. The Haven SPX Box Rate is a constant-maturity reference rate. It is not a Truth in Lending APR and not a commitment to lend.