AltStreet Weekly Markets: WP Global Growth 15's $15.5B First Sale

AltStreet's dossier for the week ending September 11, 2026 was dominated by a cluster of Form D activity inside AltStreet's tracked-entity universe. WP Global Growth 15 Partners, L.P. filed a first-sale Form D/A recording $15,521,516,356 sold to 598 investors on September 8, the largest single delta AltStreet detected this week, alongside a $1,306,105,700 first sale from Arrow Credit Opportunities III SCSp, SICAV-RAIF the same day and six further amendments detailed in the feature below.

Elsewhere, AltStreet's On-Chain Credit Spread compressed further, still entirely a function of Maple Finance's weight in the qualifying credit leg, while Polymarket-tracked prediction-market volume reached a window high. Tokenized-equity readings were mixed, with the curated cross-venue spread also hitting a window high even as GPU rental benchmarks sat flat. Window statistics below reference each series' own observation history; most windows begin in mid-July 2026 unless stated otherwise.

This week on AltStreet

This week's AltStreet reporting traced several of the filings behind these prints in more detail:

• —Boring Company Form D Shows $3.2 Billion Sold to 141 Investors, Its Fourth Raise Since 2018, another large new-money Form D print in the same week as WP Global Growth 15's and Arrow Credit's first sales
• —What Does a First Form D Tell You? Kalshi's $1.12 Billion Filing, Explained, background on reading a first Form D, as Kalshi also appears as a venue in this week's Prediction Market Activity print
• —What Does a Stalled Form D Offering Look Like? Eagle Point's $493.5M Fund, Flat Since 2023, context for the amendment-spike flags inside this week's Filings Flow
• —RD Advisors' Opportunity Fund Reports First Sales: $3.07 Million From 18 Investors, 31% of a $10 Million Offering, a smaller first-sale amendment filed the same week as the iCapital-tracked deltas below
• —RealtyMogul Income REIT Marks NAV Down to $6.85, Halves the Distribution and Says Its Columbus Office Equity Is Worth Nothing, a sponsor-reported NAV cut alongside this week's flat Concreit NAV Index print

Three things that mattered

AltStreet EDGAR Filings Flow logged 13 Form D amendment deltas this week, topped by WP Global Growth 15 Partners, L.P.'s first-sale Form D/A at $15,521,516,356 (filed September 8) and Arrow Credit Opportunities III SCSp, SICAV-RAIF's first sale at $1,306,105,700 the same day; the feature itemizes eight of the 13, including two reported decreases and four iCapital-tracked increases.

AltStreet's On-Chain Credit Spread compressed to 56 basis points from 58 a week earlier and 79 two weeks earlier, in the lower part of its observed range (28 observations since August 15, 2026, 4th percentile); Maple Finance still carries 100% of the qualifying credit leg's weight, so the spread continues to track one protocol's advertised yield rather than a market average.

AltStreet Prediction Market Activity's Polymarket headline reached $64,278,723 in 24-hour volume across 1,958 qualifying markets, a window high (96th percentile of the same 28-observation history). The two most active markets were contracts on the Federal Reserve's September 2026 meeting, at $5,909,893 for no change and $4,815,886 for a 25 basis point increase. Kalshi, the module's second tracked venue, is measured in open events and is never summed with the Polymarket dollar figure.

Inside AltStreet EDGAR Filings Flow: two first sales above $1 billion and a cluster of iCapital deltas

AltStreet's tracked-entity universe generated 13 Form D amendment deltas this week, 13 new-entity detections and eight amendment-spike flags, alongside four new Form 1-U filings, one exchange-act filing and four offering-circular supplements (253G2). The two largest prints were first sales. WP Global Growth 15 Partners, L.P. reported $15,521,516,356 sold to 598 investors (filed September 8), a year after its original Form D of September 5, 2025 reported nothing sold. Arrow Credit Opportunities III SCSp, SICAV-RAIF reported $1,306,105,700 sold the same day, and its two feeder vehicles filed alongside it: Arrow Credit Opportunities III USD Feeder SCSp at $506,750,000 and Arrow Credit Opportunities III Corporate Feeder SCSp at $382,500,000. AltStreet does not add sibling vehicles' totals together, because master and feeder filings can report overlapping capital. None of the three Arrow vehicles had a prior amount on file, so each print is the first disclosed capital rather than a change from an earlier total.

Two entities reported lower figures. Carr Properties Partnership L.P.'s annual Form D/A, filed September 9, reported cumulative amount sold of $125,000,000 with 22 investors, against $972,086,492 and 21 investors in its September 2025 amendment, a published decline of 87.14%; its sibling, Carr Properties Holdings L.P., filed the same day reporting $817,354,000 sold, up from $792,354,000. Net Lease Real Estate Fund II, L.P.'s Form D/A of September 10 reset its total offering amount to $1,057,975,000 from $1,200,000,000, down 11.84%, and reported the same $1,057,975,000 as sold to 102 investors, up from $1,021,000,000 and 86 investors in its August 20 amendment. AltStreet's methodology treats these as issuer-reported capital-formation deltas, not as an assessment of why the totals moved.

Four further deltas sit within AltStreet's iCapital-tracked universe. CastleKnight Access Fund LLC's Form D/A raised its cumulative amount sold to $109,558,000 from $18,905,000, up 479.52%, filed September 8, and CastleKnight Access Fund Ltd. rose to $24,135,000 from $5,029,000, up 379.92%, the same date. iCapital-Lexington Capital Partners XI Access Fund, L.P. filed its first sale of $36,575,000 on September 9, and Brookfield Super-Core Infrastructure iCapital Access Fund, L.P.'s Form D/A increased to $177,845,196 from $162,697,060, up 9.31%, also filed September 9.

Elsewhere in the tape

AltStreet's GPU Rental Index held its H100 and A100 80GB on-demand medians unchanged at $4.19 and $3.2315 per hour, flat across their full two-month observation windows; the RTX 4090 spot median printed at $0.25 for a second day, from two offers ranging $0.16 to $0.34. The AltStreet GPU Spread Ratio, a highest-to-lowest offer dispersion measure over the same H100 population, stood at 4.25 this week (offers ranged $2.89 to $12.29). Tokenized-equity readings diverged: the curated AltStreet Tokenized Equity Venue Spread widened to a 38.79 basis point median across eight symbols, a window high (35 observations since August 8, 2026, 97th percentile), and the AltStreet Tokenized Equity Basis printed 30.45 basis points across nine symbols on September 10. The separate CoinGecko-sourced AltStreet Tokenized Equity Venue Liquidity series recorded $125,433,142 of 24-hour volume across the 59 xStocks symbols with a print, up from $104,442,537 the day before, led by SPYx at $24,033,572 and CRCLx at $15,793,080; aggregate market cap across the 35 symbols in the companion series stood at $831,890,180. That series' longer history is a retrospective backfill over a universe that has grown from 12 to roughly 100 symbols, so no range statistic is quoted for it.

AltStreet Tracked RWA TVL, concentrated in Ondo Finance and Centrifuge, stood at $5,031,637,793, near the bottom of its two-month range (2nd percentile); on-chain private credit TVL, dominated by Maple Finance, eased to $2,928,504,800; AltStreet Tokenized Treasury AUM stood at $5,784,065,749 across its two counted products (BlackRock BUIDL 61.6%, Ondo USDY 38.4%), a lower bound on the tokenized-treasury market rather than a market total. AltStreet Reg CF Flow enumerated six new Form C offerings for the week; a seventh Form C-family filing, a Form C-U progress update, brought the week's distinct issuers to seven, and with a one-day median detection lag the newest days may still revise upward. The large-pool stablecoin yield median rose to 4.3385%, in the upper part of its range (95th percentile). AI-infrastructure tokens TAO, RNDR and AKT sat at the 81st, 33rd and 49th percentiles of their ranges; carbon token NCT printed a window low while K2 and kVCM stayed near the bottom of theirs (3rd and 6th percentile). Puro.earth's public registry, cited with attribution, showed cumulative CORC retirements at 1,084,421 against 1,875,765 issued, and the AltStreet Concreit NAV Index held at 105.49 on its single reporting vehicle. The Hiive50 index stood at 173.45, up roughly 55% over the trailing year and roughly 18% over the trailing three months, per Hiive.

Frequently asked

How many new Reg CF offerings did AltStreet's enumeration find this week, and does it reconcile with the issuer count? AltStreet's EDGAR enumeration counted six new Form C offerings for the week ending September 11, 2026, each from a different issuer. A seventh filing, a Form C-U progress update from a seventh issuer, is counted as a filing but not as a new offering, which is why the week shows seven distinct issuers against six offerings. Detection lag on the newest filings ran a one-day median, so the count may still revise upward.

How concentrated is AltStreet's tracked on-chain credit spread? The spread stood at 56 basis points this week, but the qualifying credit leg is drawn entirely from three Maple Finance pools, which carry 100% of that leg's weight; AltStreet describes this as its tracked on-chain private credit universe, not an on-chain credit market average.

Disclosures

All figures in this wrap are descriptive prints from AltStreet's own tracked-entity and market-data universes, scoped as stated in each item; window statistics reference each series' observation history, with most windows beginning in mid-July 2026 unless otherwise noted. The Hiive50 index is quoted once, with attribution, as a licensed third-party index and is not an AltStreet measurement. Nothing in this wrap is investment advice or a recommendation.