# IEX’s DEEP+ Data Fee: A New Front in the Market Data Debate
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## Introduction: A New Fee in Market Data
The Investors Exchange (IEX), long seen as a disruptor in the U.S. equities markets, has taken a new step in its evolution. On August 28, 2025, the Securities and Exchange Commission (SEC) published notice that IEX filed a proposed rule change to establish a **$3,500 monthly fee for real-time access to its DEEP+ market data feed**, ending an initial period of free distribution. Effective October 1, the move brings IEX into line with its competitors in charging for proprietary depth-of-book data, while reigniting the ongoing debate about the fairness, cost, and role of market data in modern trading.
For market participants, the change raises both practical and philosophical questions: How much should exchanges charge for proprietary data? Is IEX striking a balance between affordability and sustainability? And what does this mean for the broader fight between exchanges, brokers, and asset managers over the cost of trading infrastructure?
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## What is DEEP+?
DEEP+ is IEX’s **uncompressed order-by-order depth-of-book data feed**. It provides highly granular information on every displayed order resting on the exchange’s order book, including order IDs, timestamps, prices, sizes, side (buy or sell), and subsequent updates like modifications or cancellations. It also includes last sale information for executions on IEX and a retail liquidity identifier for securities eligible under the exchange’s retail liquidity program.
In practice, DEEP+ allows subscribers — whether high-frequency traders, asset managers, or vendors — to see the full order book at every price level, enabling them to model liquidity, run trading algorithms, and detect shifts in supply and demand. In short, it is **the lifeblood of modern electronic trading**, especially for non-display (algorithmic) uses.
When IEX launched DEEP+ in December 2024, it deliberately offered the feed free of charge during an incentive period. This helped attract subscribers and test the system. Now, after nine months of free access, IEX is moving to monetize the feed, setting a single flat monthly fee.
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## The Proposed Fee Structure
Under the SEC filing (Release No. 34-103807), IEX proposes:
– **$3,500 per month** for real-time access to DEEP+.
– No additional charges for redistribution, non-display usage, or per-user licensing.
– Continued **free access to delayed DEEP+** (15 minutes later).
– Continued access to IEX’s other feeds, such as DEEP ($2,500/month) and TOPS (top-of-book, free).
This “all-inclusive” approach differs from many competitors, who often impose **layered fee schedules**: an access fee, a distribution fee, and separate charges for non-display use (algorithmic trading or operating platforms). By comparison, NYSE, Nasdaq, and Cboe often charge tens of thousands of dollars per month for comprehensive depth-of-book products once all categories are included.
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## How Does IEX Compare?
Market share matters when pricing market data. IEX currently accounts for roughly **2.8% of U.S. equities trading volume**. While smaller than the NYSE or Nasdaq, its market share exceeds some newer competitors, such as MEMX or MIAX Pearl Equities.
A detailed comparison shows:
– **NYSE Integrated Feed**: $8,400/month plus non-display fees that can exceed $20,000.
– **MIAX Pearl Depth of Market**: $4,500/month for non-display use.
– **MEMX MEMOIR Depth**: $4,000/month.
– **NYSE National & NYSE American Integrated Feeds**: $7,500/month.
Against this backdrop, IEX’s $3,500 fee looks **modest by industry standards**, especially given its flat, non-tiered design. By eliminating redistribution and user fees, IEX signals its intention to remain competitive and lower barriers for smaller firms.
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## The Regulatory Context
Market data has long been one of the most contentious issues in U.S. market structure. Under the Securities Exchange Act, exchanges are permitted to charge for proprietary feeds, but those fees must be **“fair and reasonable, not unfairly discriminatory, and not impose an unnecessary burden on competition.”**
Over the past decade, asset managers and brokers have repeatedly challenged exchange pricing, arguing that data is an essential facility and that fees have grown excessive. The SEC has, at times, intervened, requiring exchanges to justify fee increases. Yet courts have often sided with exchanges, affirming their right to monetize proprietary products.
IEX’s filing takes pains to align with this legal framework. The exchange emphasizes that **real-time DEEP+ is optional**, that delayed data remains free, and that comparable or lower-share exchanges charge more. The design of a single flat fee is also meant to demonstrate transparency and fairness.
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## Market Data and the Economics of Exchanges
Why are exchanges so reliant on data fees? The answer lies in industry economics. Since Regulation NMS in 2007 fragmented liquidity across multiple venues, competition has driven down trading fees. For many exchanges, **market data and technology services now represent the majority of revenues**, often surpassing transaction fees.
Critics argue this creates a conflict: exchanges are incentivized to keep trading fragmented and complex to boost the value of data. Proponents counter that without the ability to monetize data, exchanges would struggle to invest in resilient technology and surveillance systems. IEX, as a smaller exchange, faces this same challenge — needing revenue diversification to fund operations while competing with giants.
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## Industry Reaction: Traders, Asset Managers, Vendors
The proposed $3,500 fee will elicit mixed reactions:
– **High-frequency traders**: For firms already paying six-figure monthly data bills, IEX’s fee is negligible. They may even welcome the simplicity of a flat, non-tiered structure.
– **Asset managers**: Large institutions will absorb the fee, but smaller buy-side firms may hesitate, especially if their strategies don’t depend heavily on IEX liquidity.
– **Data vendors**: Bloomberg, Refinitiv, and others that repackage feeds will see the fee as manageable, particularly compared with larger exchanges.
– **Advocacy groups**: Industry bodies like SIFMA and the Healthy Markets Association may still use the case as an example in their broader push for data cost reform.
Overall, because IEX’s pricing is at the lower end, it is less likely to spark legal challenges, but it contributes to the cumulative cost pressure facing traders who need access to multiple venues.
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## The Future of Market Data Policy
The SEC and Congress continue to wrestle with how to regulate market data. The introduction of the **Consolidated Audit Trail (CAT)** and the planned modernization of the **Consolidated Tape** have been touted as solutions to reduce reliance on proprietary feeds. However, proprietary depth-of-book feeds like DEEP+ remain uniquely valuable, as only exchanges can provide them directly.
In this context, IEX’s move illustrates the **balance regulators seek**: allowing exchanges to recover costs and compete, while ensuring access remains affordable and not exclusionary. The debate will continue as market data becomes increasingly intertwined with issues of fairness, transparency, and technological arms races.
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## Strategic Implications for IEX
For IEX, the DEEP+ fee marks both a maturation and a test:
1. **Maturation**: By monetizing a proprietary product, IEX joins the mainstream of exchange business models, moving beyond its image as a purely “mission-driven” alternative venue.
2. **Competitiveness**: The modest fee level may help attract firms that want depth-of-book data without the punitive costs of NYSE or Nasdaq.
3. **Brand Identity**: IEX must balance its reputation as a trader-friendly venue with the need for financial sustainability. Charging too much risks alienating supporters; charging too little risks underfunding operations.
If successful, DEEP+ could become an anchor product, contributing steady revenue while reinforcing IEX’s position in the data ecosystem.
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## Conclusion: Small Fee, Big Symbolism
The proposed $3,500 monthly fee for IEX’s DEEP+ data feed may seem like a minor change in dollar terms, but it represents a significant chapter in the ongoing story of market data. It underscores the **central role of proprietary feeds** in exchange economics, the competitive pressures between venues, and the regulatory balancing act between fair access and commercial freedom.
For traders, the immediate impact will be modest. For regulators and policymakers, however, the case highlights once again the delicate equilibrium between innovation, competition, and the costs of transparency in America’s equity markets.
As October 1 approaches, the industry will watch closely to see whether DEEP+ subscriptions remain strong and whether IEX’s strategy can carve out a sustainable niche in a market dominated by giants. The broader debate on market data fairness, however, shows no sign of fading — and IEX’s move ensures it will remain front and center.
