The Bank of England’s SONIA Stakeholder Advisory Group (SSAG) convened on 25 September 2026 to review market stability, regulatory data collection powers, and the operational implications of extending Real-Time Gross Settlement (RTGS) and CHAPS settlement hours. The unsecured overnight sterling money market remained stable, with daily volumes averaging approximately £55 billion and spreads to the Bank rate fluctuating near 1.9 basis points. Money-market funds recorded collective inflows of roughly £15 billion since the start of the year, increasing their allocation to overnight tenors due to changes in liquidity guidance and heightened geopolitical tensions.
A significant portion of the discussion focused on the Bank’s ongoing review of statutory powers for collecting sterling money market information. This initiative aims to ensure sufficient coverage and visibility as market structures evolve, potentially including data collection from group entities to preserve SONIA integrity. Concurrently, the Bank is analyzing feedback from its summer consultation on moving RTGS and CHAPS toward a near 24-hour, seven-day settlement mode. The SSAG examined how extended hours could impact SONIA’s definition, publication time, and reporting processes. One scenario discussed involved CHAPS closing at 18:00 and reopening at 20:00, creating a discrepancy between value dates and calendar dates between 20:00 and 00:00. Participants expressed a strong preference for maintaining the current 09:00 SONIA publication time, noting that delays could disrupt products referencing the benchmark.
The group also addressed the Office for National Statistics’ consultation on release times for market-sensitive economic statistics. Following ICE’s extension of trading hours for SONIA and gilt futures to 01:00 in July, participants generally favored data releases after 08:00 to align with deeper market liquidity, though a 09:30 release was considered late for pricing decisions. Regarding market activity, the Bank’s Market Intelligence team reported exceptionally high volumes in SONIA futures and options during March amid geopolitical volatility, with open interest remaining robust. While recent volatility increased volumes again, they did not reach March’s record levels. In SONIA swaps, turnover spiked in March and April before normalizing, while amounts outstanding declined slightly, possibly reflecting position unwinding and repricing of rate-cut expectations.
The SSAG’s deliberations highlight the intricate tension between modernizing infrastructure and preserving benchmark integrity. As the Bank of England pushes toward near-continuous settlement hours, the risk of operational misalignment grows. The preference for retaining the 09:00 SONIA publication time underscores the fragility of downstream financial products; even minor shifts in timing or date conventions could introduce significant friction in global markets that rely on this benchmark. The proposed discrepancies between value dates and calendar dates under extended hours scenarios reveal a critical gap in current timestamp-based conventions, requiring industry-wide adaptation rather than just regulatory adjustment.
Furthermore, the review of statutory data collection powers signals a proactive stance against potential blind spots in evolving market structures. By considering data collection from group entities, the Bank acknowledges that traditional reporting boundaries may no longer capture the full scope of Sterling Money Market activity. This move is essential for maintaining the credibility of SONIA amidst changing booking locations and regulatory landscapes. The interplay between geopolitical volatility, fund inflows, and infrastructure changes suggests that market stability is currently supported by short-term liquidity preferences, but long-term resilience depends on successful integration of extended settlement hours without disrupting established reporting and pricing mechanisms.
