Q1 2026 13F pre-wave primer — what to watch May 11-15

The next SEC 13F filing window opens around May 11-15, 2026 — 45 days after the Q1 2026 quarter end (Mar 31). Every institutional manager with $100M+ AUM must disclose their long US equity book within that window. For HoldLens readers, this is the single most data-rich event of the quarter: 30 tracked superinvestors revealing every position adjustment they made between January and March.

This primer is published 21 days early so you know exactly what to watch for. It covers: (1) what the prior wave (Q4 2025, filed Feb 17) actually showed across our tracked names, (2) the structural patterns Q1 windows tend to surface, (3) the cross-investor signals HoldLens will compute live as filings hit, and (4) how to read the data without falling for the most common 13F misreadings.

What Q4 2025 actually showed (the baseline)

At the Feb 17, 2026 deadline, HoldLens ingested all 30 superinvestor 13F-HRs for the period ending Dec 31, 2025. The headline cross-investor moves were dominated by AI-infrastructure rotation: continued buying of NVDA and META at the institutional end (Druckenmiller, Coleman), trimming at the deep-value end (Buffett continued the AAPL trim into a smaller position, held BAC). The most-bought new-position by total dollar value was GOOGL — appearing in 4 superinvestor portfolios for the first time as the antitrust overhang priced in.

Full Q4 2025 detail lives in per-investor pages — see /investor/warren-buffett/, /investor/bill-ackman/, /investor/michael-burry/ and 27 other names linked from the investors hub.

Why Q1 disclosures structurally diverge

Q1 13Fs have three structural quirks worth flagging before you read them live in May:

• Calendar-year tax-loss carryover. Positions sold in Q4 for tax-loss harvesting often get rebought in Q1 after the 30-day wash-sale window expires. Names that "disappeared" in the Feb filing may reappear in the May filing — those are not new conviction positions, they're tax-cycle artifacts. Check the cost basis if disclosed (often it isn't on 13F-HR; only 13F-CRs include it).
• Annual rebalance bias. Many fundamental managers hold rebalance discipline at calendar-year start. Q1 13Fs show the post-rebalance state — which means apparent "selling" in Q1 may simply be sizing back to target weight after Q4 outperformance, not a conviction reversal. Look at percent-of-portfolio changes, not raw share-count changes.
• Earnings-window concentration. Roughly 70% of S&P 500 names report Q4 earnings in late January / February. Position changes in Q1 13Fs reflect responses to that earnings cycle. The most reliable signal is position established in Q1 in a name that reported a downside Q4 — that's a manager taking conviction against the consensus reaction.

The four signals HoldLens will compute live

As 13F filings hit EDGAR between May 11-15, our pipeline auto-ingests each within hours and recomputes four cross-investor signals. Each is addressable as JSON for partner platforms:

1. Consensus-buy detector

Names where ≥3 superinvestors initiated or added in Q1. Historically the strongest cross-cohort signal — when value-style managers and growth-style managers agree on a name, it usually reflects a structural thesis rather than a style-rotation artifact. Q4 2025 produced 7 consensus-buy names (highest count: GOOGL at 4 buyers). Endpoint: /api/v1/13f/consensus-buys.json will refresh within 24h of each filing landing.

2. Conviction-change ranker

For each tracked superinvestor, the largest portfolio-percent shift in their Q1 disclosure relative to Q4. The biggest sells often signal a thesis break; the biggest buys signal new conviction. Weighted by the manager's historical signal accuracy (computed in our backtest results), ranked names get a ConvictionScore lift in the +50 to +100 range.

3. Sector-rotation tracker

Aggregate Q1-vs-Q4 portfolio weight by GICS sector across all 30 superinvestors. Coordinated rotations (e.g. all 30 reduce Energy by ≥1.5pts simultaneously) historically precede sector-level reratings. Q4 2025 showed a coordinated lift in Communication Services (+2.1pts cohort-wide) driven by GOOGL + META adds.

4. Contrarian-position spotter

Positions held by exactly one superinvestor with high portfolio weight (≥3% of book). High-conviction-low-consensus is the textbook contrarian signal. Burry's AAPL puts in late 2024 sat in this bucket; so did Ackman's CMG re-entry in early 2025. Q1 2026 contrarian positions get a flag in the per-investor view immediately on filing.

How to read 13Fs without getting fooled

Three durable misreadings to avoid:

• 13Fs are 45-day-old data. The quarter ended Mar 31. The filing isn't due until May 15. The position could have been exited in April. Treat 13Fs as evidence of historical conviction, not current holdings. The SEC Signals trilogy combines 13F (45-day lag) with insider Form 4 (2-day lag) and 8-K material events (4-day lag) precisely to triangulate timing.
• 13Fs report long-only US equity. Short positions, debt, options (with exceptions), foreign equity, private holdings — none of it shows. A manager going net-short a name via puts will look like they "sold" the long, not like they shifted to a short thesis. Always check the 13F-CR (confidential treatment request) addendum if the manager files one — that's where delayed disclosures hide.
• "Buffett bought X" is usually wrong. Berkshire Hathaway has multiple portfolio managers (Buffett, Ted Weschler, Todd Combs). Not every BRK position is a Buffett pick. Position sizes <$1B are typically Weschler/Combs decisions. HoldLens flags this in the Berkshire view; other 13F trackers conflate the three managers and produce misleading "Buffett conviction" claims.

What HoldLens will publish on filing day

Within 6 hours of the first Q1 2026 filings hitting EDGAR (expected May 11-12 for early filers; May 14-15 for the rest), HoldLens will ship:

• Per-superinvestor diff page — every position changed, formatted as add/trim/exit/new
• Cross-investor consensus-buy + consensus-sell digest, sortable
• Sector-rotation summary (Q1 vs Q4 weight deltas)
• The "State of 13F Filings — Q1 2026" flagship report (8,000+ words, expected May 17-18)
• Refreshed JSON API endpoints for every per-investor + per-sector view

Pre-announce alerts ship via /api/v1/quarters.json for partner platforms wanting to subscribe to publication-window events. Email alerts for early-access drafts available with HoldLens Pro (€9/mo).

The honest framing

HoldLens does not predict what the Q1 13Fs will show. We instrument them faster + with cleaner cross-investor synthesis than any other public tracker. Our edge is structural data clarity, not directional forecasting. If you want forecasts, you want a different site. If you want the cleanest per-investor + cross-investor view of what 30 of the smartest portfolio managers in the world actually did in Q1 — within 6 hours of the filings hitting EDGAR — that's what we ship.

Same disclaimer applies: 13F data, not investment advice. The 45-day lag is real and must be read alongside the 2-day-lag Form 4 insider data + 4-day-lag 8-K material events for a complete picture.