Public-Data Research Monitor

SLR Watch

Monitoring how the Supplementary Leverage Ratio shapes large-bank Treasury holdings and balance-sheet behavior—using free public regulatory data from FFIEC Call Reports, FR Y-9C, FR Y-15, NY Fed dealer statistics, and FINRA TRACE.

+2.47pp
Treasury Inventory Increase
Low-headroom banks increased Treasury holdings relative to controls after the 2020 temporary SLR exclusion (broad sample, p = 0.002).
+9.86pp
Safe-Asset Composition Shift
Covered-bank subsidiaries shifted their safe-asset mix toward Treasuries rather than Fed reserve balances.
75%
Family Co-Movement
Bank and parent Treasury-share changes moved in the same direction in three-quarters of linked quarter-over-quarter comparisons.
Inference note. Under parent-level clustering in the flagship sample (15 clusters), the headline Treasury coefficients retain their sign and approximate magnitude but lose conventional significance (p ≈ 0.17). The right language is directional evidence, not a settled causal estimate.

Core Results

Event-Study Findings

The flagship design compares balance-sheet-constrained banks to less-constrained peers around the April 2020 temporary SLR exclusion. Constrained banks—especially covered-bank subsidiaries—appear to have increased Treasury holdings more than comparison banks.

Coefficient Comparison: Treasury Inventory / Assets
DiD coefficient across three sample/specification variants · Outcome: Treasury inventory scaled by total assets
Broad sample (HC1)
Flagship per-parent (HC1)
Flagship clustered (parent)
Filled = p < 0.05  |  Hollow = p ≥ 0.05

What holds up

The low_headroom_treated and covered_bank_treated coefficients are positive and economically meaningful across all three sample variants. In the broad sample, both are significant at the 1% level.

What does not

The high_ust_share_treated coefficient is near zero and insignificant everywhere. The flagship-clustered results lose conventional significance, so the headline should be framed as suggestive rather than definitive.

232
Broad sample observations
21
Distinct entities (broad)
180
Flagship sample observations
15
Parent clusters (flagship)

Research Design

Method

A panel event study around the April 2020 temporary SLR exclusion, using difference-in-differences with entity and time fixed effects.

Why SLR Matters for Treasury Markets

The Supplementary Leverage Ratio requires large banks to hold Tier 1 capital against all on-balance-sheet assets and certain off-balance-sheet exposures, without risk-weighting. Unlike risk-based capital ratios, SLR treats Treasuries the same as corporate loans in the denominator. For banks near the binding constraint, every dollar of Treasuries consumes scarce leverage capacity—creating a direct link between capital regulation and Treasury-market intermediation.

GSIB parent holding companies face a 5% enhanced SLR (eSLR) minimum, while their covered insured-bank subsidiaries must maintain 6% to be classified as well-capitalized. The 2025 final rule recalibrates these buffers to 3% + 0.5 × method 1 surcharge for parents and 3% + min(1pp, 0.5 × parent surcharge) for subsidiaries, effective April 2026.

The 2020 Natural Experiment

On April 1, 2020, the Federal Reserve temporarily excluded U.S. Treasury securities and deposits at Federal Reserve Banks from the SLR denominator for holding companies. The exclusion expired on March 31, 2021. This created a clean before/during/after window for estimating how leverage-ratio relief affects bank Treasury demand.

The event window runs from 2019–Q1 through 2021–Q4, with the pre-period ending at 2020–Q1 and the post-treatment period beginning at 2020–Q2. This gives four pre-treatment quarters and seven post-treatment quarters.

1

Sample Construction

The universe covers U.S. GSIB parents, major insured-bank subsidiaries, large non-GSIB controls, and U.S. IHCs of foreign banking organizations. The broad sample includes 21 entities (232 bank-quarter observations). The flagship per-parent sample restricts to the single largest insured subsidiary per parent family—15 entities, 15 parent clusters, 180 observations—to avoid double-counting families with multiple large subsidiaries.

2

Treatment Definitions

Three treatment arms, each splitting the sample on a pre-shock characteristic measured as of 2019–Q4:

  • Low SLR headroom — banks whose pre-shock headroom (actual SLR minus required SLR) fell below the sample median. These banks had the most to gain from the exclusion.
  • Covered-bank subsidiary — insured depositories subject to the 6% well-capitalized threshold, versus non-covered peers facing only the 3% minimum. This captures the regulatory intensity channel.
  • High pre-shock Treasury share — banks with above-median Treasury inventory as a share of assets. This arm tests whether banks already holding more Treasuries responded differently; it does not produce a robust result.
3

Specification

The baseline is a two-way fixed-effects difference-in-differences model:

Yit = αi + γt + β · (Treatedi × Postt) + εit

Entity fixed effects (αi) absorb time-invariant bank characteristics; quarter fixed effects (γt) absorb common macro shocks including aggregate market conditions. The coefficient of interest β measures the differential change in outcomes for treated banks after the exclusion. Standard errors use HC1 heteroskedasticity-robust inference in the baseline, with parent-family clustering as the strictest check.

4

Outcome Variables

All outcomes are drawn from FFIEC Call Report schedules and scaled by total assets to ensure comparability across bank sizes:

  • Treasury inventory (fair value) — the primary outcome; sum of HTM, AFS, and trading-account Treasuries
  • Fed reserve balances — balances due from Federal Reserve Banks
  • Reverse repos and trading assets — captures intermediation activity
  • Deposit and loan growth — tracks whether changes reflect reallocation or general balance-sheet expansion
5

Market Controls

Quarter-level market conditions—NY Fed primary-dealer positions, UST repo volumes, and TRACE aggregate par value—are absorbed by the quarter fixed effects in the baseline specification. The repo additionally reports an interaction sensitivity (Treatedi × Postt × Markett) and a weaker auxiliary specification without time fixed effects that lets raw market levels enter directly. Neither overturns the baseline read.

Clustered-inference caveat. With 15 parent clusters in the flagship sample, asymptotic cluster-robust variance estimates are known to over-reject. The repo reports both HC1 and parent-clustered standard errors; readers should weight the clustered column as the conservative bound. The headline coefficients retain their sign and approximate magnitude under clustering, but p-values rise from < 0.01 to roughly 0.17.

Mechanism Evidence

How Constrained Banks Responded

Five current extension reports build a mechanism story: reallocation away from other balance-sheet uses, a shift in safe-asset composition toward Treasuries, consistency with family-level transmission, and a possible reduction in trading-balance-sheet use.

Balance-Sheet Reallocation

The Treasury response came alongside weaker expansion elsewhere on the balance sheet. Constrained banks appear to reallocate scarce capacity rather than simply growing everything.

Net Treated − Control Change by Outcome
Positive = treated group changed more; Negative = control group changed more · 2019–2021 event window
Treasury Inventory Fed Balances Deposit Growth Loan Growth
Low Headroom +2.47pp +0.26pp −3.52pp −1.65pp
Covered Bank +1.97pp −0.45pp −3.98pp −2.32pp

Safe-Asset Composition

The main difference is composition within safe assets, not just the level of Fed balances. Constrained banks shifted the safe-asset mix toward Treasuries by roughly 9–10 percentage points more than controls.

Safe-Asset Reallocation
Net treated − control change by safe-asset category
Treasury Share of Safe Assets
Treasury Inventory / Assets
Fed Balances / Assets

Treasury Intermediation Tradeoff

Constrained banks reduced trading-balance-sheet use while absorbing more Treasuries. The strongest market linkages are between treated-minus-control trading-assets gaps and NY Fed dealer-position context (correlation up to 0.82).

Trading Assets vs. Treasury Inventory
Net treated − control change · Top: trading assets (negative); Bottom: Treasury inventory (positive)
Trading Assets / Assets
Treasury Inventory / Assets

Parent–Bank Transmission

The insured-bank Treasury result sits inside broader family-level balance-sheet behavior. Linked-family analysis covers 100 bank-parent quarter observations across 15 parent families.

Directional Co-Movement
Share of quarter-over-quarter changes moving in the same direction for bank and parent
High vs. Low Surcharge Families
Dumbbell comparison: red = high surcharge, blue = low surcharge
High-Surcharge Families
Low-Surcharge Families

High-surcharge families show lower average bank headroom (0.87pp vs. 1.90pp), consistent with tighter SLR constraints driving more pronounced balance-sheet responses.

Broader View

Policy Regime Context

A longer quarterly panel places the 2020 event in context. The temporary exclusion window stands out most clearly in reserve accumulation, while Treasury share rose modestly. Over the subsequent QT era, parent trading-assets share declined as dealer positions and TRACE par volume grew.

Regime Comparison
Key balance-sheet shares across policy periods (29 quarters, 2019–2026)
Earlier regime
Later regime

Market Growth

  • NY Fed dealer net UST positions grew 118.9% over the full sample
  • UST repo volume grew 91.6%
  • TRACE total par volume grew 15.2%

Balance-Sheet Shifts

  • Insured-bank Fed-balance share nearly doubled during the temporary exclusion (7.75% to 15.09%)
  • Parent trading-assets share fell from 9.66% to 9.03% between the exclusion and QT eras
  • Treasury share rose modestly from 6.15% to 6.45%

Extension

Which Constraint Matters in Which Regime?

The 2020 event study isolates the SLR channel. But leverage headroom is not the only pressure that shapes bank Treasury capacity. This module decomposes balance-sheet constraints into leverage, duration-loss, and funding pressure across insured-bank and parent/IHC panels through 2025Q4.

Constraint Mix by Regime and Panel
Share of bank-quarters where each constraint scores highest · Scorecard combines SLR headroom, unrealized-loss proxies, deposit/funding metrics, and liquidity buffers
Leverage
Duration Loss
Funding
65.9%
Banks: duration-loss dominant in 2022–2023
63.0%
Parents: duration-loss dominant in 2022–2023
539
Insured-bank observations
393
Parent / IHC observations
64.8%
Linked families match in 2022–2023
48.6%
Both bank and parent duration-loss dominated

Regime shift

In the 2022–2023 duration-loss window, duration pressure becomes the dominant constraint for both insured banks (65.9%) and parents/IHCs (63.0%). By late QT normalization, insured banks still lean duration loss at 42.1%, while parents shift back toward leverage at 35.4%.

Family alignment

Linked families match on the dominant constraint in 64.8% of duration-loss-window family-quarters, and both sides are duration-loss dominated in 48.6% of those observations. The 2022–2023 regime is the first period where joint duration-loss dominance becomes common.

Supporting regressions

On the parent panel, higher duration pressure is associated with higher Treasury share in the 2022–2023 window (0.027, p = 0.001) and lower Treasury share in late QT (−0.034, p = 0.026). Bank-side results are weaker. This is supporting evidence, not a separate causal claim.

Scope note. The decomposition extends the project's question from “did SLR relief matter in 2020?” to “which constraint matters in which regime?” Its results are descriptive and should be read as a complement to the 2020 event study, not a standalone causal design.

Public Data

Data Sources

All data comes from free public regulatory filings and market-data APIs. No proprietary feeds, no paywalled datasets.

FFIEC Call Reports

Insured-Bank Panel

The main empirical panel. Bulk schedule files provide bank-level total leverage exposure, Tier 1 capital, Treasury holdings, Fed balances, repos, trading assets, loans, and deposits.

Quarterly Automated
FR Y-9C

Parent Holding Companies

Parent-level Tier 1 capital, total leverage exposure, Treasury holdings, and trading assets. Historical files from the Chicago Fed archive; current data via NIC automation.

Quarterly Automated
FR Y-15

Systemic Risk Indicators

Method 1 surcharge context and GSIB systemic-intensity overlays. Snapshot files parsed via Playwright; surcharge scores from the OFR Basel workbook.

Annual Automated
NY Fed Primary Dealers

Market Context

Weekly aggregate data on dealer Treasury positions, transactions, repo, reverse repo, and securities lending. Collapsed to quarterly market-context overlay via the official Markets Data API.

Weekly Automated
FINRA TRACE

Treasury Trading Context

Free public aggregate data on Treasury par volume and trade counts. Weekly archive files for 2019–2022; monthly workbooks for 2023+. Treated as market-level context only.

Weekly / Monthly Semi-automated
OFR BSRM

Enrichment

Bank Systemic Risk Monitor scores used to build the annual Basel-method surcharge overlay. Provides ranking context and systemic-intensity data for GSIB identification.

Mixed Automated

Pipeline Overview

1

Ingest

Automated downloaders fetch Call Report bulk ZIPs, FR Y-9C files, FR Y-15 snapshots, NY Fed API data, and TRACE aggregates into standardized raw storage.

2

Stage

Raw files are extracted, merged by schedule, and normalized into Parquet with variable lineage and quality checks.

3

Derive

A curated crosswalk links entities across sources. Insured-bank and parent panels are assembled with rule-aware SLR headroom, Treasury-capacity metrics, and market overlays.

4

Analyze

The event-study workflow runs DiD estimates, event-time coefficients, and extension reports. All outputs are written to reproducible report directories.

Output

Reports

The repo generates structured report outputs covering the core event study, five current extension analyses, market context, and a live constraint-decomposition module.

Findings Memo

Integrated summary of all results, caveats, and recommended framing for the v1 release.

2020 Event Study

Core DiD estimates and event-time coefficients for the temporary exclusion window. Includes broad, flagship, and flagship-clustered variants.

Balance-Sheet Reallocation

Treated-versus-control change decomposition across Treasury, Fed balances, deposits, and loans.

Safe-Asset Absorption

Composition analysis separating Treasuries from Fed reserve balances within the safe-asset portfolio.

Parent–Bank Transmission

Linked-family analysis comparing bank-subsidiary and parent-company balance-sheet changes within the same corporate family.

Treasury Intermediation

Sensitivity analysis linking trading-assets and Treasury-inventory responses to dealer-position and repo market context.

Policy Regime Panel

Broader quarterly panel with regime averages across pre-exclusion, temporary exclusion, post-exclusion normalization, and QT era.

Market Context

NY Fed dealer statistics and TRACE aggregate data providing Treasury-market backdrop for the bank-level analysis.

Constraint Decomposition

Cross-regime comparison of leverage headroom, duration-loss pressure, and funding stress for insured banks and parents through 2025Q4, with family-alignment summaries and a supporting interaction-regression layer.