SITREP #011 · WEEKLY SITUATION REPORT · 21–25 SEP 2026

Broad, Not Deep

The overnight tape ran $22.1B across five sessions, up 13 percent on the week, but the headline hides the shape: notional peaked Tuesday and faded 37 percent into Friday. When Friday's breadth finally recovered, the size did not come with it. Underneath, the 30-year Treasury hit 5.50 percent, its highest since 2004, and the tape registered the shock directly, with breadth collapsing to 36 percent on Thursday's broad down night.

Sapinover Intelligence · Sunday, September 27, 2026 · Overnight figures computed from the three-venue pipeline and reconciled to the dollar against the week's recap; rates and the earnings calendar verified at source; market closes from the captured snapshot; the venue filing read on SEC EDGAR.

00BLUF

//The Stack

Five layers of market plumbing, and where each one stands this week. Click any layer for the detail.

01The Tape

Five sessions, Monday through Friday, by overnight trade date. The week opened heavy and thinned every night. Monday's session ran $5.21B across three venues; Tuesday was the peak at $5.74B; then three straight declines to $3.61B on Friday.

Notional in millions. Breadth is the share of BlueOcean overnight names printing up into the open. Moon reported zero Monday (a Sunday-evening session, expected) and small size the rest of the week. Three-venue week total $22.05B against $19.44B the week before, +13.4 percent. BlueOcean ran $17.35B, Bruce $4.39B, Moon $0.31B.

The midweek collapse is not subtle. Thursday's 36.4 percent breadth is the lowest of the week and marks the broad down night, the overnight tape's direct read on the rate shock that hit the same day. Friday's bounce to 68.3 percent looks like a recovery until you set it against notional: $3.61B, essentially the week's trough. A session can be broad and shallow at once, and this one was. That gap between breadth recovery and notional recovery is the participation warning to carry into next week.

The names underneath

The semiconductor and memory complex held 49.0 percent of BlueOcean nightly notional this week, ranging 43.2 to 53.5 percent across the five sessions, with memory alone at 16.8 percent. It is another week near half, the pattern the tape has run since midsummer, and it happened during the exact week the complex drove the index. SOXL, the leveraged semis wrapper, led at $2.71B. SanDisk and Micron took the next two spots at $1.46B and $1.40B, both memory. Micron reports Wednesday, so the tape's third-largest overnight name is also this week's first scheduled fundamental test.

02The Rate Shock

The week's binding constraint was the long end of the Treasury curve. A global bond selloff, driven by renewed inflation fear after a hot September activity read midweek, took the 30-year yield to 5.50 percent by Friday, its highest level since 2004. The 30-year was below 5 percent as recently as early July. The 10-year printed as high as 5.22 percent Thursday, the highest since June 2007, before easing to about 5.18 percent Friday. This was not a US-only event; long-end yields made multi-year highs across developed markets.

At the index level the week read calm and concentrated. Weekly moves, by proxy:

A 3.2 percent Nasdaq-100 week sitting on top of a negative Russell 2000 is the definition of narrow leadership. Semiconductors and a few mega-caps did the work; small caps, energy and rate-sensitive names lagged. VIX closed Friday at 14.87, down on the session, after expanding midweek as yields surged. Crude settled $92.41, down 2.3 percent on the day, though the weekend argued against treating that as a durable floor. A sub-15 VIX under a 5.50 percent long bond is the surface calm the internals do not fully support, and the same split the overnight tape shows in breadth against size.

03Forward Calendar

• Wednesday, September 30. August core PCE, 8:30 AM ET. The first full inflation print after the September hike and the week's macro hinge. Against a 5.50 percent 30-year, a hot core reading reopens the yield repricing that defined last Wednesday.
• Wednesday, September 30. Micron reports fiscal Q4 after the close. The same day as PCE. Micron is our third-largest overnight name this week, so the inflation print and the semiconductor complex's first fundamental test land on the same tape. The tape can split: rates down and chips up, or both hit at once.
• Friday, October 2. Nonfarm payrolls. The second macro gate after PCE, and the read on whether the domestic, small-cap side of the market that lagged all week stabilizes.
• October 2. SIP UAT weekends begin. Six industry User Acceptance Testing weekends run through December 4 over production multicast channels.
• October 27–28. FOMC, no SEP. One week before the midterms. After a hot September and a 5.50 percent long bond, the statement language on inflation will matter more than the decision.
• December 6. SIP 23x5 production launch. Consolidated market data extends to Sunday 9 PM through Friday 8 PM ET. The overnight data gap closes.

The rail

04A New Venue

One filing worth a line. Admiral Securities LLC filed to operate an NMS Stock ATS built around T+0 same-day settlement, to our knowledge the first US equity and ETF venue designed around same-day settlement rather than the standard T+1. It clears through Vision Financial Markets, runs the regular session only, and has no FINRA reporting MPID yet, so it does not appear in the overnight tape above.

We flag it because of how it surfaced. Sapinover's automated ATS-N monitor, which now reads every Form ATS-N filing across the venue universe from SEC EDGAR each week, caught the Admiral filing on its first run, before the operator had announced the launch publicly. The overnight venue map has been the franchise's recurring beat; the monitor is how we now watch it fill in, in real time and unattended.

The same monitor also caught two cover-page-only ATS-N amendments this cycle: PureStream (Sep 23) trimmed a minimum order size and lowered a fee, and IntelligentCross (Aug 31) filed an overnight trading session for its ASPEN book, each recorded on the cover page ahead of any restated form. Read at source on SEC EDGAR.

05Get SITREP

##Sources

SITREP is a weekly situation report on market structure. Overnight notional figures reflect Sapinover's overnight pipeline and are not comparable to full-market consolidated volume. This analysis is for information only and is not investment advice, a recommendation, or a solicitation. For methodology see the support page.