Description

BSE modifies MPS subscription cycle from monthly to weekly and introduces monthly billing based on peak MPS allocation for equity derivatives trading members.

Summary

BSE has announced significant changes to the Trading Member level Throttle Limit/Messages Per Second (MPS) framework in the Equity Derivatives segment. The key modifications include shifting from monthly to weekly MPS subscription cycles and implementing monthly billing based on peak MPS allocation during the calendar month.

Key Points

  • MPS subscription cycle changed from monthly to weekly effective November 6, 2025
  • Trading members can submit MPS revision requests every Thursday
  • Revised limits become effective from T+2 trading day (following Monday)
  • Monthly billing will be based on peak MPS limit during the calendar month
  • For work weeks spanning two months, both months will be billed at the peak MPS limit of that week
  • First submission window opens Thursday, November 6, 2025 for limits applicable from November 10, 2025

Regulatory Changes

Subscription Cycle Modification:

  • Previous: Monthly MPS revision cycle
  • New: Weekly MPS revision cycle with Thursday submission deadline
  • If Thursday/Friday is a trading holiday, requests accepted on previous trading day
  • Revised limits effective from T+2 trading day per existing practice

Billing Methodology Change:

  • Billing frequency: Monthly (unchanged)
  • Billing basis: Changed to peak MPS limit during the calendar month
  • Special provision for cross-month weeks: Both months billed at the peak MPS limit of the overlapping week

Compliance Requirements

  • Trading members must submit MPS revision requests through UCC portal
  • Submissions allowed every Thursday (or previous trading day if Thursday/Friday is holiday)
  • Requests subject to Exchange review before approval
  • All existing terms and conditions of member level throttle/MPS limit policy remain applicable

Important Dates

  • October 28, 2025: Notice issued
  • November 6, 2025: First weekly MPS revision request submission window opens
  • November 10, 2025: Week when revised limits under new weekly cycle become applicable

Impact Assessment

Operational Impact:

  • Greater flexibility for trading members to adjust MPS limits weekly based on business needs
  • Faster turnaround time for capacity adjustments compared to monthly cycle
  • Enhanced ability to respond to market conditions and trading volume changes

Financial Impact:

  • Monthly charges now based on peak MPS allocation during the month
  • Trading members may face higher costs if they increase limits even temporarily during the month
  • Cross-month week billing provision ensures consistent charging for overlapping periods

Trading Impact:

  • More responsive capacity management for derivatives trading operations
  • Better alignment of infrastructure costs with actual usage patterns
  • Reduced waiting period for members needing capacity increases

Impact Justification

Operational change affecting trading members' MPS limits and billing methodology in equity derivatives segment. Provides more flexibility with weekly subscription cycles but impacts cost structure.