LOOMIS SAYLES & CO L P
SEC Form 13F institutional filer · CIK 0000312348
13F-HR · 270 reported holdings · 2026-03-31
Asset management firm, subsidiary of Natixis Investment Managers.
Reported long-US-equity value
$60.94B
Top-10 concentration
63.8%
LOOMIS SAYLES & CO L P — $60.9B AUM allocation strategy
LOOMIS SAYLES & CO L P files SEC Form 13F and reports $60.9B of long US equity value across 270 reported holdings for 2026-03-31.
Its largest sector bet is Communication Services 24.8%, followed by Information Technology 23.6% and Consumer Discretionary 15.4%.
The top 10 holdings account for 64% of reported value — a conviction-weighted book concentrated in its best ideas. The sector and industry splits below are of the same reported value. Track quarter-over-quarter adds, trims, new positions and exits below — sourced from SEC 13F filings, public domain.
LOOMIS SAYLES & CO L P — latest SEC 13F insights
Reported long-US-equity value (13F AUM)
$60.9B
total across 270 reported holdings · 2026-03-31 · excludes shorts, cash, non-US
Top-10 concentration
64% of value
higher = narrower conviction; lower = spread / hedging
Biggest adds (shares)
+$NFLX +743K sh · +$160M+$ORCL +715K sh · −$669M+$IVZ +686K sh · −$3.59M
Biggest trims (shares)
−$ECHO −368K sh · −$26.9M−$MNST −363K sh · −$137M−$BA −351K sh · −$331M
Exited to nil (held last quarter, gone now)
$CMG ($34.2M last qtr)$ADBE ($33.3M last qtr)$BLDR ($30.4M last qtr)$ES ($3.55M last qtr)$DASH ($2.94M last qtr)
Sector allocation (share of reported value)
each slice is a share of the reported long-US-equity value — smaller sectors and the rest of the book roll into “Other holdings”
Qtr shift = share-point change vs the prior quarter's filing — first period tracked for this filer; the column fills in with the next quarterly refresh.
Industry allocation (share of reported value)
- Interactive Media & Services16.5%—
- Semiconductors11.7%—
- Movies & Entertainment8.2%—
- Application Software8.2%—
- Automobile Manufacturers7.7%—
- Broadline Retail6.3%—
- Biotechnology5.4%—
- Aerospace & Defense4.6%—
- Other holdings31.3%—
the finer GICS cut of the same book — same denominator — smaller industries roll into “Other holdings”
Qtr shift = share-point change vs the prior quarter's filing — first period tracked for this filer; the column fills in with the next quarterly refresh.
Top S&P 500 holdings
10 of 10 rows · sorted by Value ↓
| Ticker | Holding | Shares | Value | Δ QoQ | Weight |
|---|---|---|---|---|---|
| $NVDA | NVIDIA Corporation | 41M | $7.15B | +636K | 11.7% |
| $GOOG | Alphabet Inc. Class C Capital Stock | 17.3M | $4.99B | +197K | 8.2% |
| $TSLA | Tesla Inc | 12.7M | $4.7B | +5.36K | 7.7% |
| $META | Meta Platforms Inc | 7.45M | $4.26B | +43.1K | 7.0% |
| $AMZN | Amazon.com Inc | 18.3M | $3.82B | +363K | 6.3% |
| $NFLX | Netflix Inc | 38M | $3.65B | +743K | 6.0% |
| $BA | Boeing Company | 14.1M | $2.8B | -351K | 4.6% |
| $V | Visa Inc | 9.25M | $2.8B | +32K | 4.6% |
| $ORCL | Oracle Corporation | 16.9M | $2.49B | +715K | 4.1% |
| $MSFT | Microsoft Corporation | 6.06M | $2.24B | +66.6K | 3.7% |
…and 260 more holdings in the full 13F filing (top positions only shown).
SEC Form 13F data sets · public domain · 45-day filing lag · >$100M AUM managers · as reported
← All 13F filers·← QuantOrb.pro
How to read Δ QoQ — the five insight categories, and the caveats
The categories. Analysts, quants and retail traders look past total portfolio value to isolate actionable signals. Five categories matter.
Conviction & concentration shifts
New positions vs complete exits — a brand-new stock signals high conviction; a full liquidation suggests a broken thesis or tax-loss harvesting. Aggressive sizing — look at share count, not dollars: a 20% share increase during a drawdown is strong dip-buying. Concentration — a narrowing top-5/10 means conviction; spreading capital across more names means hedging.
Sector & macro allocation rotations
Aggregating Δ QoQ moves across sectors shows where smart money is leaning in or sneaking out — rotating out of growth into defensives or energy, for example. The fund's total long equity exposure quarter-over-quarter is a proxy for overall institutional risk appetite.
Crowding & smart-money consensus
When several managers initiate or expand the same stock in the same quarter, that is institutional consensus. Contrarian reads: top pickers buying hard into a beaten-down name the market is selling.
Derivative & option overlays
Reported call/put changes indicate whether managers are adding downside hedges or leveraging upside exposure. Note: a long increase may be half of a market-neutral pair trade.
Who reads this
| Retail "cloners" | High-conviction ideas to replicate ~45 days after quarter-end. |
| Corporate IR | Which funds bought or dumped the stock, before the next call. |
| Quant / algo traders | Cross-sectional factor inputs: flow, momentum, ownership. |
Four caveats before you trade on it
- 45-day lag — holdings are quarter-end; positions may already be closed.
- Long-only — 13Fs miss shorts, pair trades and cash.
- No non-US / fixed income — the picture is US equities plus options.
- Corporate actions — splits and spinoffs distort raw share deltas.
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