Type: Price
Mid price/rate.
For OTC swaps this is the mid-market mark (for example, as defined by CFTC).
For uncleared OTC swaps, LegMidPx (2346) and the MidPx (631) fields are mutually exclusive.
Added in protocol FIX.4.3
See in: FIX.4.3, FIX.4.4, FIX.5.0, FIX.5.0SP1, FIX.5.0SP2.