Bank of New York Mellon's Q4 2025 13F looks like a photocopied S&P 500 — NVDA, AAPL, MSFT, AMZN in the expected order. Then you reach position #12: Berkshire Hathaway (BRK/B) at $5.6 billion.
Berkshire at #12 in an otherwise pure index-mirror is the most interesting deviation in one of the most boring filings in the database.
The filing
| Metric | Value |
|---|---|
| 13F AUM | $568B |
| Top holdings | NVDA, AAPL, MSFT, AMZN — standard S&P 500 order |
| Notable deviation | BRK/B at #12 ($5.6B) |
| IVV (S&P 500 ETF) | Also in top holdings |
| Overall character | Index-mirror with a tilt |
Why BNY Mellon's filing looks like the S&P 500
BNY Mellon is the world's largest custodian bank. Their 13F reflects:
- Index fund management: BNY Mellon Wealth Management runs index and quasi-index strategies
- Custodial aggregation: Some reported positions may include assets held in custody
- Institutional client mandates: Managing money for pension funds, endowments, and foundations that typically want benchmark-like exposure
The result: a top-10 that is virtually indistinguishable from the S&P 500 weights.
The Berkshire deviation
Berkshire Hathaway at position #12 with $5.6B is notable because:
Where BRK sits in the S&P 500
Berkshire is typically around #7-10 in the S&P 500 by weight. At #12 in BNY's filing, it could be:
- Slightly underweight vs. index (positions 7-11 pushed it down)
- Or at index weight but bumped by other holdings that are slightly overweight
Why BRK stands out
In an otherwise perfectly index-like filing, ANY deviation is worth noting. BRK at #12 could reflect:
- Active tilt toward Buffett: BNY Wealth Management may deliberately overweight BRK as a "quality value" conviction — a stock that provides market exposure with a value tilt
- Client preference: Institutional clients may specifically request BRK exposure (it's a common "proxy for the market with Buffett's judgment" allocation)
- Custodial artifact: BNY holds Berkshire shares in custody for various institutional clients, which might aggregate into the 13F
The custodian bank 13F pattern
Custodian banks file some of the most index-like 13Fs because their business model IS the index:
| Custodian | 13F AUM | Deviation from S&P 500 |
|---|---|---|
| BNY Mellon | $568B | Minimal — BRK at #12 is notable |
| State Street | $3.4T | Minimal — pure index manager |
| Northern Trust | $1.2T+ | Minimal — wealth + custody |
How to read custodian filings
- Top 10 matches S&P 500: Expected. No signal.
- Small weight deviations (±0.5%): Could be timing, rebalancing, or fund composition differences
- A stock appearing outside expected index position: This is where the signal lives
- ETF holdings (IVV, SPY): Reflects internal fund-of-funds or client collateral
The IVV holding
BNY Mellon also holds iShares S&P 500 ETF (IVV) — which is a BlackRock product. A custodian bank holding a competitor's ETF alongside individual stock positions suggests:
- Some client mandates use ETFs for core exposure
- IVV may be used as collateral or for cash management
- The ETF sits alongside individual stock positions that replicate the same index (double exposure to the same names through different vehicles)
What BNY's filing tells you
About the market
- The S&P 500's top-heavy structure is so dominant that even a $568B custodian bank's portfolio is essentially a capitalization-weighted mirror
- NVDA, AAPL, MSFT, AMZN dominate every institutional portfolio regardless of the manager's DNA
About BNY Mellon specifically
- Their wealth management arm runs close to benchmark
- The BRK tilt suggests a deliberate (but small) quality/value accent on top of index exposure
- They're not trying to generate alpha through stock selection — they're providing institutional-quality market exposure with minor tilts
About how to analyze similar filings
When a filing is 95% index-like, focus your analysis on the 5% that deviates. BRK at #12 is that 5% for BNY Mellon.
Originally published at 13F Insight
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