Why Exchanges Charge for Market Data
Summary
The document examines why exchange market data is sold rather than made freely available, including whether public access would improve transparency and whether historical tick data could be released without charge. The responses frame exchange data as both a potential public good and a service produced by venues that contribute to price formation. They argue that fees can help fund exchange infrastructure, while removing data charges might shift costs to trading or participation fees.
The discussion also distinguishes raw data from services such as collection, storage, real-time delivery, and error filtering. Market structure matters: the answers describe differences between US and European consolidated quote data, and mention a European proposal for delayed access to consolidated trade data while pre-trade order book data remained outside its scope. These are contextual claims from the discussion, not a detailed cost analysis. The document does not quantify infrastructure expenses or settle whether regulatory bodies should distribute historical data, so it offers economic and institutional explanations rather than evidence that one pricing model is best.
Key ideas
- Exchange data can be viewed as a public good, but individual venues help produce the prices represented in the data.
- Market data fees can contribute to the cost of operating exchanges and their technology infrastructure.
- Data vendors may charge for filtering, storage, and real-time delivery as well as for access to raw exchange feeds.
- Consolidated market data arrangements differ across regions and can affect how reliably traders identify the best available price.
- The discussion provides possible justifications for fees but does not quantify costs or compare pricing models empirically.
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Full text
# Why isn't all market data free? # Why isn't all market data free? I am hoping any answers can be threaded somewhere between "don't be naive" and starting a quasi-political flame. Transparency is suppose to be good for markets and also a social good. The market reflecting the availability of all known information is a premise accepted by many. Why then is the disparity between access to available information based on what a market participant can afford so widely and readily accepted? I acknowledge that there is some cost involved in transmitting real-time data, order flow, etc., for instance, but how significant is it? Is it impractical technically or financially when it is amortized over all market players? Less controversial, why is tick data, etc., not made available free to the public at the end of day? Why is this any more proprietary or the property of a market than the outcome of a baseball game? If by making it freely available data brokers have less incentive to store data why not make that the responsibility of the regulatory agencies (e.g. SEC or whatnot)? Are there technical or other reasons, aside from powerful financial incentives, to keep things the way they are? ## Answer by lehalle (score 4, accepted) https://quant.stackexchange.com/a/3592 On the paper you are right: the market data are close to a public good and could be free because of that. Nevertheless in a fragmented landscape, each trading venue is contributing specifically to the price formation process. Each of them invest that for, and it is thus not unfair to get revenue that for. If you look at Europe (I am not speaking here about the Reg NMS-driven context for the US), only the historical markets actual ask revenue for their market data. BATS Europe announced that it will ask for fees soon. Nevertheless in the MiFID review actually under scrutiny in Europe, a consolidated post trade tape (i.e. of trades) will have to be free after 15 minutes. It seems to be a good balance. But pre trade data (i.e. orderbooks) are not in the scope of this. You may know that if the US has a pre trade consolidated tape (in fact three tapes A, B and C), in Europe it is not the case. MiFID could not structure the market microstructure that way because of the numerous clearing and settlement prices across Europe, where you have only one in the US. Consequently if you see a best price in the orderbooks in US: it is your best price for sure. In Europe it is not 100% sure because for a buyer the best ask can be cheaper on NYSE-EuroNext than on BATS-Chi-X, but after considering the clearing and settlement prices, it could be no more the case. ## Answer by SRKX (score 6) https://quant.stackexchange.com/a/3597 I think Lehalle answer is very good but I would like to answer in a slightly different manner, maybe from an economical point of view. I think the real question is What are market data fees charged for?. Assume the whole data was available to anybody for free, then nobody would be willing to pay for it. There are essentially two main reasons why the data costs something: - The data itself is the property of someone and is not available for free (limited supply resulting in monopolistic environment). - If the raw data was publicly available then you would have to identify the added value from a provider for which you are required to pay a fee. 1) Data availability Market data is provided by exchanges, it's not there for anybody to observe. If there were no exchange, there would be no real single price for a security. So the exchange is providing a service allowing investor to trade at some centralized price. They basically own this data in a sense. You could try setting up an exchange providing live data for free, but you would see that it costs money (from an infrastructure point of view) so you need to generate money from all possible sources to make it interesting to have an exchange. You could arguably remove market data fees but you would increase transactions costs or some subscription fee to be able to participate to the exchange. So basically, you want to use the service offered by the exchange (which includes market data) and you hence pay for that service. 2) Added value There is some added value to the raw data of an exchange. Essentially, the provider will apply filters to the data thus removing possible misprints to make sure that the data is actually correct. Besides, the data has to be collected and stored using some IT infrastructure which you have to pay for. This is particularly important for tick data and you can see pretty quickly that you wouldn't be able to manage live ticks if you do not have yourself a huge IT department ready to handle this. You also pay for the way data is delivered to you; setting up a real-time push service to deliver data does cost money. So, you actually pay for the services of the data providers and because setting up an exchange would not be possible without charging fees (you pay the existence of the exchange). ## Answer by Suminda Sirinath S. Dharmasena (score 3) https://quant.stackexchange.com/a/3598 Exchanges are becoming increasingly for profit enterprises and cost of technology and infrastructure to support the vast amount of data generated needs to be covered. If you look at the financials of NYSE you see data related services does not generate much revenue, perhaps just to cover the cost of providing the services though more detail analysis on this is needed. So nominal fees to coves part of the technology costs is justifies and is needed in the business sense.
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