CME MDP 3.0 (Market Data Platform)

MDP 3.0 is CME Group's market data protocol for CME Globex: binary messages in Simple Binary Encoding sent over UDP multicast channels, carrying incremental book and trade updates, instrument definitions, status changes and recovery snapshots. Retail platforms rarely read it directly; they receive a vendor's version of it, such as Rithmic's feed or Databento's GLBX.MDP3 dataset.

Senzoukria · Glossary · Updated September 2026


What the protocol carries

  • Incremental refresh messages: book changes by price (MBP) and by order (MBO), trade summaries, statistics such as session high and low, settlement and open interest.
  • Security definitions: every instrument's identity and parameters, including tick size and matching algorithm.
  • Security status: open, pre-open, halted or reserved, as during a velocity logic pause.
  • Market recovery: periodic snapshots from which a consumer can rebuild a book after missing data.

How it is delivered

Messages are encoded in Simple Binary Encoding, a fixed-layout binary format designed for fast decoding, and packed into numbered packets sent over UDP multicast. Each channel is published twice, on an A feed and a B feed, so that a consumer can fill a packet lost on one from the other. A packet sequence number lets the consumer detect any gap; if both feeds miss a packet, it has to recover from a snapshot or a replay.

Worked example

One aggressive buy order for 25 contracts meets 15 contracts from two resting orders at 5,000.25 and 10 contracts from one order at 5,000.50. The exchange publishes this as one trade summary event with two price-level entries, 15 at 5,000.25 and 10 at 5,000.50, each with its number of resting orders, marked with the buy side as aggressor, together with the book updates that remove that liquidity. How many prints a platform finally shows for it depends on how the vendor turns that event into trades.

Why a trader should know the name

Many properties that decide what a footprint can show start here: whether the aggressor side is explicit, how one aggressive order is split into prints, how implied prices are published, how halts are signalled. A vendor can preserve, aggregate or drop each of them.

In Senzoukria

The application never connects to MDP 3.0 itself. Its CME data arrives through Rithmic's R | Protocol or through Databento, whose CME dataset is named GLBX.MDP3 after the protocol; the Databento modules require a live licence on that dataset for the footprint and heatmap switch. What each source preserves of the exchange feed is a property of that source.

Common mistakes

  • Assuming every CME data product delivers the exchange's full detail.
  • Comparing trade counts between vendors that aggregate the trade summary differently.

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Frequently asked questions

Can I connect to MDP 3.0 from home?
The multicast feed is distributed through CME's connectivity options, such as colocation and dedicated lines, and licensed by CME. Individual traders almost always receive it through a vendor that decodes it and forwards its own format.
Is the Databento GLBX.MDP3 dataset the same as MDP 3.0?
It is Databento's normalised dataset built from CME's MDP 3.0 feed, offered in schemas such as trades, MBP-1, MBP-10 and MBO. The schema you subscribe to decides how much of the original detail you receive.

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