A New Exchange, a Rule Rewrite, and a Record Issuance Tape: U.S. Market Structure Hits an Inflection Point

Three developments landed within days of each other in early July 2026 that, taken together, mark the most significant reshaping of U.S. equity market structure in two decades. The Texas Stock Exchange begins live trading on Monday, July 7. The SEC has proposed rescinding the NMS Order Protection Rule — the regulatory backbone of how equities are routed and priced since 2005. And the first half of 2026 produced a record $251 billion in IPO proceeds, the largest six-month issuance haul in history. None of these events in isolation would qualify as a watershed. Their convergence does.

The Texas Stock Exchange Opens for Business

The Dallas-based Texas Stock Exchange (TXSE) will commence a phased trading rollout on Monday, July 7, starting with member-only trading on test symbols before bringing thousands of NMS stock symbols online progressively through July. All National Market System symbols should be available for trading on TXSE by the end of the month, according to exchange officials. Exchange-Traded Products are targeted for Q3, with corporate listings expected in Q4.{{cite:texastribune_txse}}

TXSE is the first genuinely new national securities exchange to launch in decades, and it enters with $275 million in backing from BlackRock, Citadel Securities, and other major financial institutions — up from the initial $120 million announced at the exchange’s June 2024 unveiling.{{cite:texastribune_txse}} The exchange is entirely electronic with a physical presence at the Bank of America Tower in Dallas’s Uptown neighborhood, positioning itself as a competitor to the NYSE-NASDAQ duopoly that has governed U.S. listings for a generation.

The competitive response has been swift. Both NYSE and NASDAQ have already established Texas-branded branches — NYSE Texas and NASDAQ Texas — a move TXSE officials interpret as validation that the Dallas financial corridor, nicknamed “Y’all Street,” now commands Wall Street’s attention.{{cite:texastribune_txse}} Over the past 20 years, investment banking jobs in Texas have grown 111%, compared with 16% in New York, and Texas now employs more financial-services workers (939,600) than either New York or California.{{cite:texastribune_txse}}

The honest assessment is that TXSE’s near-term impact on trading flows will be modest. It will take years of gradually attracting corporate listings — the revenue engine for any exchange — before TXSE can meaningfully challenge NYSE or NASDAQ’s decades of incumbent advantage.{{cite:texastribune_txse}} But the launch matters for a different reason: it adds a third national venue at precisely the moment the SEC is proposing to dismantle the rule that compels brokers to route orders to whichever exchange displays the best price. The interaction between more venues and less mandatory routing is where the real structural change lives.

The SEC Proposes Rescinding Rule 611

On June 11, 2026, the SEC proposed rescinding Rule 611 of Regulation NMS — the Order Protection Rule, also known as the trade-through rule — along with Rule 610(e), the prohibition on locked and crossed markets. Comments are due by August 17, 2026. If adopted, this would represent the most significant change to U.S. equity market structure in two decades.{{cite:sidley_nms}}

Rule 611, adopted in 2005, requires every trading center to establish and enforce written policies designed to prevent “trade-throughs” — executing trades at prices inferior to the best displayed quotation on any other venue. It was designed as a regulatory backstop to the duty of best execution, ensuring that investors’ displayed limit orders could not be bypassed.{{cite:sidley_nms}} Rule 610(e) prohibits exchanges from displaying quotations that lock or cross each other, preventing the visual confusion of simultaneous matching bid and offer prices across venues.{{cite:sidley_nms}}

The SEC’s rationale for rescission rests on several claims. The agency argues that today’s markets are “highly automated, interconnected, fast, and competitive,” with sophisticated routing technology that makes mandatory order protection obsolete. It cites Rule 611’s role in increasing costs and complexity — including the proliferation of order types, venue fragmentation, and the practical pressure on broker-dealers to connect to every exchange that displays a protected quotation, regardless of trading volume. And it explicitly references the emergence of tokenized NMS stocks and on-chain trading venues as a reason to reassess the rule.{{cite:sidley_nms}}

The open questions are substantial. Without Rule 611, broker-dealers face heightened best-execution pressure and must carefully document why they executed at a trade-through price. Locked and crossed markets could appear in displayed quotes, potentially confusing investors and complicating routing decisions.{{cite:sidley_nms}} The relationship between the rescission and the CT Plan’s proposed revenue allocation amendment — which would impose a 5:1 cap on each exchange’s quote-to-trade revenue ratio — could create economic pressure on low-volume exchanges that have been able to earn outsized market-data revenue by posting quotations with minimal actual trading.{{cite:sidley_nms}}

Chairman Paul Atkins also extended temporary exemptive relief from the compliance dates for Rules 610(c) and 612 — the 2024 amendments on access fee caps and minimum tick sizes — until November 2027, signaling a willingness to revisit the entire pricing and display ecosystem.{{cite:sidley_nms}}

Putting numbers on the uncertainty: I’d estimate a 60% probability that the rescission is adopted in substantially proposed form by Q1 2027, given the current commission’s deregulatory posture and the explicit references to tokenization as a motivating factor. The 40% against includes the possibility that comment letters from institutional investors and large broker-dealers raise enough concerns about locked markets and best-execution documentation gaps to force material modifications — perhaps preserving a watered-down version of the trade-through prohibition for retail orders.

H1 2026: A Record $251 Billion IPO Haul

While the structural plumbing is being rewritten, the volume flowing through it has already set records. Through June 26, 2026, U.S. issuers raised $251 billion in IPOs — surpassing the prior midyear record set during the 2021 listing boom, according to Renaissance Capital data reported by Reuters.{{cite:ecmsource_ipo}}

Two landmark deals drove the total: SpaceX’s $86.2 billion IPO on June 12 (priced at $135, closing its first session at $161, a 19% gain), and Alphabet’s $85 billion follow-on equity raise to fund its AI infrastructure buildout. Together, those two transactions alone are larger than all U.S. IPO proceeds from 2023, 2024, and 2025 combined.{{cite:ecmsource_ipo}}

Sources: Renaissance Capital Q2 2026 review; Reuters/Yahoo Finance, June 27, 2026.{{cite:ecmsource_ipo}}

But the headline overstates the breadth. Two deals account for roughly 68% of the half-year total. Strip them out and you still have a record-paced market — 11 deals cleared $1 billion, and Goldman Sachs noted volumes “are advancing rapidly” across products, not just mega-cap tech{{cite:ecmsource_ipo}} — but concentration is the defining risk. Cerebras Systems, the wafer-scale AI chipmaker, debuted May 14 at roughly $5.55 billion and opened about 89% above its IPO price, the largest AI-chip IPO on record.{{cite:arcstone_ecm}}

The composition tells a sector-rotation story. Healthcare anchored Q1 with 7 deals and +43.6% average returns before capital rotated toward AI in Q2, where technology staged a dramatic reversal from -5.8% in Q1 to +16.7% year-to-date.{{cite:arcstone_ecm}} Convertible issuance is running at roughly 2x the 2025 pace ($34 billion through April), with roughly half AI-linked, anchored by Oracle’s $5 billion mandatory convertible preferred and CoreWeave’s $4 billion deal.{{cite:arcstone_ecm}} Follow-on proceeds reached $42 billion in Q1 alone, with sponsors accounting for an estimated 67% of March volume as vintage 2017–2020 private equity funds press for LP liquidity.{{cite:arcstone_ecm}}

The New Listings Still Coming

The July calendar is already producing fresh supply. Securitize (NYSE: SECZ), the BlackRock-backed tokenization platform, began trading July 2 after completing its merger with the Cantor Equity Partners II SPAC. The deal raised $400 million and valued the company at $1.25 billion, with 71% of the SPAC’s cash pool retained rather than redeemed. Shares rose roughly 3% on the first session.{{cite:fortune_securitize}} Securitize has said it will issue a tokenized version of its own stock — a concrete bridge between the traditional listing process and the on-chain trading venues the SEC references in its Rule 611 proposal.{{cite:fortune_securitize}}

Sable Offshore (NYSE: SOC) priced concurrent offerings on July 1: 32.5 million common shares at $3.08 per share and $300 million in 6.5% convertible senior notes due 2031, with proceeds earmarked for debt repayment. The stock rose 10.4% in premarket trading following the pricing.{{cite:seekingalpha_sable}}

Abivax announced full exercise of underwriters’ options on July 2, bringing gross proceeds of its offering to $920 million (€807 million).{{cite:abivax_offering}} BrightSpring Health Services (NASDAQ: BTSG) announced a 15-million-share secondary offering by existing holders including KKR, accompanied by a concurrent share repurchase — a sponsor monetization pattern consistent with the PE-driven follow-on volume that defined Q1.{{cite:btsg_secondary}}

The Overnight Trading Frontier

A less-discussed but structurally significant development: on May 27, 2026, the 27th Amendment to the NMS Plan to Address Extraordinary Market Volatility was filed, establishing temporary price band protections for overnight trading.{{cite:sec_overnight}} This coincides with the NSCC’s April 2026 rule change — approved by the SEC on May 27 — extending its clearing capability to support expanded equity trading hours, and Nasdaq’s SEC-approved proposal to expand its own trading hours.{{cite:sec_overnight}}

The trajectory is clear. U.S. equity markets are moving toward extended or near-24-hour trading sessions. The limit-up/limit-down price band framework, originally designed for regular-session volatility control, is being extended to cover overnight activity — a necessary prerequisite for any meaningful expansion of trading hours. When combined with the proposed rescission of Rule 611, which would give venues more flexibility in how they handle quotations, the overnight session becomes a genuine frontier for new market structure rather than a thinly traded afterthought.

What to Watch Next

• TXSE launch execution (July 7 and beyond). Whether the phased symbol rollout proceeds without technical disruption. Any latency, matching engine, or connectivity issues in the first weeks will shape issuer and broker-dealer willingness to engage with the new venue.

• Rule 611 comment letters (due August 17). The volume and tone of institutional investor pushback versus broker-dealer and exchange support will indicate whether the rescission proceeds cleanly or faces material modification. Pay particular attention to letters from large asset managers concerned about limit-order protection and from tokenization platforms supportive of the change.

• Q3 IPO calendar front-loading. Morgan Stanley has flagged that Q3 deals are likely front-loaded ahead of midterm-election volatility, meaning July and August supply may compress before a potential fall slowdown.{{cite:ecmsource_ipo}} The pace of S-1 filings from PE sponsors — identified by JPMorgan as the dominant H2 supply source — will pre-signal whether the calendar can sustain Q2’s pace.{{cite:ecmsource_ipo}}

• Renaissance IPO ETF (NYSE: IPO) performance. The cleanest market proxy for newly listed share performance. When broken IPOs spike, sentiment turns and the new-issue window closes. SpaceX’s post-debut volatility — shedding roughly $400 billion in market cap over a four-session stretch in late June, including a single-day 16% decline — is an early warning that even record demand at issuance does not guarantee clean aftermarket performance.{{cite:ecmsource_ipo}}

• Tokenized equity venues. Securitize’s plan to issue a tokenized version of its own stock, combined with the SEC’s explicit citation of tokenization in the Rule 611 proposal, suggests the first meaningful on-chain trading of NMS securities could arrive within the rule’s comment period. Whether these venues integrate with consolidated market data — or operate in a parallel quote environment — will be a defining structural question.

The base case is that the U.S. equity market is entering a period of structural experimentation not seen since the decimalization and Reg NMS reforms of the early 2000s. A new exchange, a deregulatory rule rewrite, record issuance, overnight session expansion, and tokenization are all moving in the same direction: toward more venues, more flexibility, more hours, and more ways to trade the same stocks. Whether that produces tighter spreads and better execution for investors — or more fragmentation and more confusion — is the open question the next twelve months will answer.