Issuance window

Primary markets are not continuously open. A deal needs a period long enough to market it during which conditions do not move against the book, and underwriters will not launch a transaction they cannot fill, because in a firm commitment underwriting the unsold paper lands on their own balance sheet.

Windows close for reasons that have nothing to do with the issuer. A jump in volatility, a sharp move in credit spreads, a geopolitical event, or a run of poor aftermarket performance in recent deals will all shut one. They also close for calendar reasons: results blackout periods, the August lull in Europe, and the stretch around year end.

The consequence is that issuance clusters rather than flowing evenly. A backlog builds while the window is shut and then several deals arrive in the same fortnight once it reopens, which is why a busy week in the primary market says as much about the previous quiet month as about that week.

For an issuer the practical discipline is to take financing when it is available rather than when it is needed. A company with a maturity eighteen months away that refinances early at a spread it does not love has bought certainty; a company that waits for a better level may find the window shut when the maturity is close enough to give it no choice.