Yemeni forces are to announce a military operation at 08:30 local time (06:30BST/01:30EDT)

Pre-announcements of military operations from Yemeni actors have, in recent episodes, been associated with the Houthi movement and its campaign against Red Sea shipping, and the transmission channel in those cases has run through freight and insurance: war-risk premia for Bab el-Mandeb transits, carrier decisions to reroute via the Cape of Good Hope, and knock-on effects in container rates and, at times, crude and European gas via longer ton-miles. The case distinction that matters is whether the announced operation is maritime (shipping disruption, immediate freight repricing) or directed at regional land targets (broader escalation risk, oil supply security rather than transit costs). Precedent is that the initial headline typically precedes the details by hours, so the early move tends to be a risk premium in crude and shipping-linked names that retraces if the actual operation proves contained, and extends if it draws a military response from coalition navies. Worth watching are the follow-through statements, any claims of strikes on vessels or bases, and whether the US or allied naval presence in the region issues its own response, since escalation sequences in past episodes have been defined by the retaliation round rather than the opening strike. Given the advance notice itself, the scheduled 06:30 BST slot is the reference point for the next information step.