Allocations

Allocations are internal, shared between investment firms and custodians

• Allocations (A₁, A₂, … Aₙ) are “preallocated” in the OMS for each Execution and are then “filled” or aggregated by the relevant Fills (Fill₁₁, Fill₁₂, …) received from the EMS.
• Completed Allocations are sent to Back Office for settlement.

Sample are as follows

1. EMS receives these Fills from the market for a child order:

   Fill 1:   800 shares  @ $185.49 (NASDAQ)
   Fill 2:   500 shares  @ $185.50 (NYSE)
   Fill 3: 1,200 shares  @ $185.48 (DARK POOL)
   ─────────────────────────────────────────
   Total:  2,500 shares @ $185.488 avg
   

2. OMS has these pre-existing allocation slots:

   Fund A:  1,200 shares  (50%)   ← existed before any fill arrived
   Fund B:    800 shares  (30%)
   Fund C:    500 shares  (20%)
   

3. When fills complete → OMS stamps the allocations:

   Fund A:  1,200 shares @ $185.488
   Fund B:    800 shares @ $185.488
   Fund C:    500 shares @ $185.488
   

This differs from Broker Order, where it will only show what is traded with the broker:

broker_id     : BO_4348f
side          : sell
status        : filled
ordered_qty   : 2,500 shares
filled_qty    : 2,500 shares
average_price : 185.48
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