HKMA sets Base Rate at 4.25% following 25-basis-point

Cresthaven AnalyticsIntelligence Brief

Headline

HKMA sets Base Rate at 4.25% following 25-basis-point increase in US federal funds rate target range

Executive Summary

The HKMA set the Base Rate at 4.25% on September 17, 2026, effective immediately, following a 25-basis-point increase in the US federal funds rate target range on September 16, 2026. The adjustment is formula-driven and non-discretionary.

Bottom Line

The HKMA Base Rate stands at 4.25% with immediate effect as of September 17, 2026, set by formula following the Federal Reserve's 25-basis-point upward adjustment to the US federal funds rate target range. The Discount Window Discount Rates, computed from the Base Rate, reprice accordingly. Cresthaven reading: institutions with Discount Window access or Hong Kong dollar funding costs indexed to the Base Rate carry updated pricing exposure from the date of this announcement.

Key Regulatory Signals

Base Rate Reset to 4.25%: The HKMA has set the Base Rate at 4.25% with immediate effect as of September 17, 2026, applying the higher of two formula inputs: 50 basis points above the lower end of the US federal funds rate target range, or the average of the five-day moving averages of the overnight and one-month HIBORs. The formula-driven result is 4.25%.
Formula Inputs at the Decision Point: The 50-basis-point-above-lower-bound calculation produced 4.25%, while the HIBOR-based average stood at 2.50%. The Base Rate is set at the higher value per the pre-set formula.
Discount Window Pricing Moves in Tandem: The Base Rate serves as the foundation for computing Discount Rates on repurchase transactions through the HKMA Discount Window. Cresthaven reading: licensed banks and institutions accessing the Discount Window face repriced collateralized borrowing costs effective immediately.
Linked Exchange Rate Mechanism in Operation: The adjustment reflects the automatic transmission of US monetary policy through Hong Kong's linked exchange rate system, under which the Base Rate formula is designed to track US federal funds rate movements without discretionary HKMA intervention.

Regulatory Delta

The HKMA Base Rate has been adjusted multiple times during the current US rate cycle. This adjustment continues that pattern of automatic, formula-driven transmission.
The 25-basis-point increase in the US federal funds rate target range on September 16, 2026 is the direct mechanical trigger. The HIBOR-based alternative stands at 2.50%, well below the formula output.
No cross-agency coordination or legislative action accompanies this adjustment. It is an automatic output of the linked exchange rate framework.

Materiality Classification

LOW — A formula-driven, non-discretionary rate adjustment with no new compliance obligation; the Base Rate change is an automatic output of the linked exchange rate mechanism and imposes no new regulatory requirement on any institution.

Intelligence Outlook

Monitor the HKMA for any subsequent Discount Window operational notices or guidance following this Base Rate adjustment.