Where can I get free data on multifamily REITs? Three ledgers, one feed

SEC EDGAR Company Search & Filing Archive is the regulatory spine of the cohort. Six issuers anchor it - Equity Residential, AvalonBay Communities, Mid-America Apartment Communities, UDR, Essex Property Trust and Camden Property Trust - and each carries the full trail: annual 10-Ks with property-level schedules, 10-Q quarterlies, 8-K current reports, proxies and insider forms. Verified against Equity Residential / ERP Operating LP (CIK 0000906107, trading as VMRK since the August 18, 2026 symbol change), the record holds 1,006 recent filings including eleven consecutive 10-Ks reaching back to 2015.

Cross-sections come pre-built too: the frames view returns one concept across all filers for a calendar period, and the CY2025Q1 Revenues frame alone carried 1,934 facts - a peer revenue panel assembled without touching a document. See the XBRL company facts entry for how the structure works.

Nareit Residential REIT Sector Page is the sector briefing card, published by the association behind the FTSE Nareit indexes. One surface, three layers. An FTSE-sourced overview sizes the sector as of 7/31/2026: 15 residential REITs, a 3.96% dividend yield, a 5.74% year-to-date total return, -1.61% for July and -7.43% for full-year 2025.

The third layer names the players: a 28-company directory with ticker, headquarters, stock price and one-year total return stamped to the August 21, 2026 close. Treat the page's disagreeing counts as labeled views rather than an error - 15 in the FTSE overview, 18 cited as index-listed constituents, 28 in the directory - because non-traded and recently listed names live in the roster too. When the comparable set itself needs widening past residential, the Nareit REIT & Public Real Estate Company Directory enumerates 166 companies filterable by property type.

Deeper than the filings era, if the layers are chosen deliberately. The Nareit REIT Market Data Reports Hub, cross-listed from Diversified Real Estate Activities, holds monthly FTSE Nareit index values and returns spanning December 1971 through June 2026 - 664 rows across 42 columns in the flagship workbook, indexed to exactly 100.0 on December 31, 1971. Each block - All REITs, All Equity REITs, Mortgage REITs - ships total, price and income return beside index level and dividend yield, and June 2026 All REITs closed at an index level of 11,717.261 on a 4.02% yield. Annual-grain studies get their own companion record covering 1972 through 2025 (Nareit Annual Index Values & Returns).

That is five decades of listed-real-estate returns sitting beneath fundamentals that mostly begin with structured reporting, inside a document trail reaching the mid-1990s. One scope note travels with it: the workbook is index-level rather than apartment-specific, so the multifamily cut comes from pairing it with per-issuer tagged facts rather than reading the aggregate as a sector proxy.

For household-level work, the American Housing Survey (AHS) National Microdata ships its biennial wave with 55,669 household records (about 1,180 variables) and a 16,834-record mortgage table carrying interest rate, payment amount, loan class and HELOC balance - the household across the street, priced into buying rather than renting. And FRED - Federal Reserve Economic Data contributes the discount-rate half of a valuation: hundreds of thousands of macro and rate series, up to 100,000 observations per request, so numerator inputs and the capitalization rate arrive from the same shelf.

Four grains, arriving together - which is the whole integration problem in one glance:

# filing-grade fact row - Equity Residential / ERP Operating LP
cik        : 0000906107   entity : EQUITY RESIDENTIAL (VMRK since Aug 18, 2026)
form       : 10-K         filed : 2026-02-13    period : 2025-12-31
accession  : 0001193125-26-051433                document : eqr-20251231.htm
concept    : us-gaap:Revenues     val : 682329000     fy 2020  fp Q1  frame CY2020Q1

# market row - quote card, largest name in the cohort
ticker : VMRK   price : 63.66   mktcap : 24.61B
trailing_pe : 28.68   fwd_dividend_and_yield : 2.81 (4.26%)   street_target : 74.04

# demand row - CPS/HVS quarterly vacancy
year_quarter : 2026 Q2   rental_vacancy_us : 7.3   principal_cities : 8.0

Each row keeps its own unit, period and provenance stamp - dollars of revenue here, millions of sector FFO there, a market-close stamp on every quote cell - so the layers stack without lying to each other. That discipline is what lets one table hold a 10-Q's revenue figure, the sector's cash-flow conversion, the multiple the market pays for it and the vacancy rate behind next quarter's rents. Assembling those grains from separate shelves means reconciling schemas that were never meant to meet; delivered together, the join keys arrive pre-agreed - CIK, ticker, period, quarter.

Across all of them the pattern repeats: the value is not any single number but the stack - filing-grade proof underneath, sector benchmarks beside, market pricing on top, the demand clock ticking beneath everything.

Start with the question, then take the smallest record that answers it. Statement-line fundamentals want the SEC EDGAR Company Search & Filing Archive; the sector denominator wants Nareit; multiples and yields want the quote-page record; the fifty-year return series wants the market data reports hub. For the filing ledger walked end to end, see the companion post on multifamily REIT filings as a managed feed.