S3 Capital

Overview

S3 Capital is a New York private real estate lender founded in 2013 by the principals of Spruce Capital Partners, specialising in construction and bridge loans to housing-oriented developers. Its own published figures put it past $10 billion in construction loan originations, across a "small balance" line of $1m to $20m and a middle-market line of $20m to $250m.

It is the lender behind the $29 million construction financing on Mendy Schwimmer's planned 55-unit building at 877 Grand Street in East Williamsburg, recorded in July 2026 under the vehicle name S3 RE 875 Grand Funding LLC.

Source: S3 Capital

Transactions Tracked

877 Grand Street Financing (Jul. 2026) $29M

Lender

Named as party2 on the July 2026 financing documents: $29,000,000 in all, with the $9,500,000 consolidation counted once (it already includes the $1,000,000 mortgage recorded the same day). PincusCo separately reports Mendel Schwimmer signing a $29 million construction loan with S3 Capital for a 55-unit East Williamsburg project -- the same developer, neighbourhood, unit count and project as this record.

Known Entity Names on ACRIS Records

• S3 RE 875 Grand Funding LLC — Lending vehicle on the 877 Grand Street construction package PincusCo reports Mendel Schwimmer signing a construction loan with S3 Capital for a 55-unit mixed-use project in East Williamsburg -- the same developer, neighbourhood, unit count and project as the loan ACRIS records to this vehicle.
• S3 RE 52 4th Ave Funding LLC — Intermediate holder on the 52 4th Avenue financing Same naming convention and lending profile, but no source names S3 Capital as a party to this loan. Listed, not claimed.
• S3 SB Real Estate Credit A Trust — Lender on the 32-40 4th Avenue assemblage (546 Pacific Street) financing, and on the 858 Atlantic Avenue purchase mortgages The "SB" matches S3 Capital's published small-balance line, and both loans -- $6.5m at 546 Pacific Street, and $11.1m plus $2.9m at 858 Atlantic Avenue -- sit inside that band, but no source names S3 Capital as the lender on either. Listed, not claimed.
• S3 RE Perpetual Yield Funding LLC — Lender on the 995 President Street financing Same naming convention, no source naming S3 Capital on this loan. Listed, not claimed.

Related Properties

Sources

1. S3 Capital — S3 Capital
2. Mendel Schwimmer signs $29M construction loan with S3 Capital for mixed-use in East Williamsburg — PincusCo
3. S3 Capital Lends $45M to Build Williamsburg Apartments — Commercial Observer

The 877 Grand Street construction financing: a $9.5 million agreement, which consolidates an existing $8.5 million loan with a new $1 million mortgage, plus $15.5 million and $4 million mortgages, all recorded to one lender in July 2026. The S3-prefixed vehicles on other Brooklyn transactions are not counted, because S3 Capital has not been named as the lender on those specific loans.