Diamond Hill Q1 2026: Trim Everything, Add Microsoft

Diamond Hill Capital Management, a value-focused manager, reported a $15.99B U.S. equity book for the quarter ended March 31, 2026 (Form 13F-HR, accession 0001217541-26-000005, filed 2026-05-07). The reported value fell 18.1% from $19.52B — a steep drop — and the filing shows why: Diamond Hill trimmed nearly its entire book, cutting most large positions by 17% to 37% in share terms. Against that broad reduction, it made one striking move in the opposite direction, raising Microsoft (MSFT) by 400%.

The contrast is the story. AIG was cut 21%, Berkshire Hathaway's Class B shares 17%, Colgate-Palmolive (CL) 25%, Texas Instruments (TXN) 37%, and ConocoPhillips (COP) 30%. Reducing this many positions by this much in one quarter points to portfolio-wide de-risking or outflows, not stock-by-stock decisions — while the quintupling of Microsoft stands out as a deliberate, concentrated addition.

For a value manager, building a large Microsoft position is itself notable: it suggests Diamond Hill found the megacap's valuation acceptable on its terms even as it pared back across the rest of the book.

A value book under pressure

The largest positions reflect Diamond Hill's value orientation: AIG at 4.04%, Berkshire Hathaway's Class B at 3.81%, Abbott (ABT) at 3.45%, insurance broker Aon at 3.00%, and Colgate-Palmolive at 2.88%. Energy (Diamondback Energy (FANG), ConocoPhillips), financials (Capital One (COF)), and Texas Instruments round out a diversified value lineup.

With 187 positions and the ten largest at roughly 29% of the book, Diamond Hill runs a diversified value portfolio. But the reported value has now declined for several consecutive quarters, from $22.65B at the end of 2024 to $15.99B — a slide that, combined with the broad trimming, is consistent with net outflows from the strategy.

Trim everything, add Microsoft

The position changes are almost uniformly negative — the kind of even, across-the-board reduction that signals a portfolio-level action rather than a series of individual sell decisions. Texas Instruments (-37%), ConocoPhillips (-30%), and Colgate (-25%) saw the deepest cuts.

The lone exception, Microsoft's 400% increase, is the signal worth watching. When a value manager raising cash across its book simultaneously builds one position fivefold, that name carries unusual conviction — it is what Diamond Hill chose to buy while selling almost everything else.

What it means for 13F readers

Diamond Hill is a clean example of reading broad versus selective trading. The even cuts across the book point to de-risking or redemptions, while the Microsoft build is the deliberate, high-conviction exception. The signal to watch next quarter is whether the value slide stabilizes and whether the Microsoft position holds. Track the firm's quarter-over-quarter holdings on the Diamond Hill filer page.

FAQ

What is Diamond Hill Capital Management?

Diamond Hill is a value-focused investment manager. It reported a $15.99B U.S. equity 13F book for the quarter ended March 31, 2026, across about 187 positions.

Why did Diamond Hill's 13F value fall 18% in Q1 2026?

The reported value fell to $15.99B from $19.52B, driven by broad trimming across most positions plus market movement — a pattern consistent with net outflows from the strategy.

What was Diamond Hill's biggest move in Q1 2026?

It raised Microsoft by 400% in share terms — the lone large addition in a quarter where most positions were cut by 17% to 37%.

What are Diamond Hill's largest holdings?

Its five largest positions are AIG (4.04%), Berkshire Hathaway Class B (3.81%), Abbott (3.45%), Aon (3.00%), and Colgate-Palmolive (2.88%) — a diversified value book.