CBN mops up N3.69 trillion in single-day aggressive OMO auction

The Central Bank of Nigeria (CBN) conducted one of its most aggressive single-session Open Market Operations (OMO) auctions on May 21, 2026, mopping up a combined N3.692 trillion across two instruments in a dramatic escalation of its liquidity tightening campaign.

This is according to OMO auction results published by the apex bank and analysed by Nairametrics.

The apex bank’s financial data show that the combined offer of N600 billion across a 33-day, and a 138-day bill was overwhelmed by investor demand as total subscriptions hit N3.692 trillion, more than six times the amount on offer.

The outcome marks a sharp departure from the May 12, 2026, auction, where the CBN exercised significant restraint, accepting only N116 billion of N872 billion in total subscriptions across a 35-day and a 70-day bill.

What the data is saying

The May 21 auction results reveal a financial system awash with investible funds chasing the CBN’s high-yield paper.

• On the 33-day bill, subscriptions reached N1.525 trillion against a N300 billion offer, representing a 5.1x oversubscription, with the CBN accepting the entire amount at a marginal rate of 21.57%.
• The longer 138-day bill drew even stronger demand — N2.168 trillion in bids against a N300 billion offer, a staggering 7.2x oversubscription, with all bids accepted at a marginal rate of 19.97%.
• The short-tenor bill commanded a higher rate (21.57%) than the longer-dated instrument (19.97%).
• The willingness of the CBN to accept all subscriptions — rather than rationing as it did on May 12 signals a deliberate policy decision to drain as much excess liquidity from the banking system as possible in a single session consistent with concerns about inflationary money supply.
• Combined net sales of N3.692 trillion in a single day represent an extraordinary intervention by any measure since 2026.
• Broader CBN financial data reinforces this picture. The Standing Deposit Facility (SDF) — the primary channel through which banks park surplus cash with the CBN overnight — fell dramatically from N6.103 trillion on May 20 to N5.797 trillion on May 21.
• It plunged further to N2.703 trillion on May 22, a two-day collapse of over 55%, reflecting the direct impact of the OMO absorption, as funds were drawn from bank balance sheets and locked up in OMO instruments.

Opening balances in the banking system also fell from N102.47 billion on May 20 to N78.96 billion on May 22 — a three-day contraction of approximately 23%.

More insights

Beyond the OMO auction itself, the CBN’s financial settlement data for the review period reveals significant primary market activity running concurrently.

• On May 21 alone, primary market sales — comprising Nigerian Treasury Bills (NTBs) and FGN Bonds — recorded N829.33 billion, coinciding with the settlement of the May 20 NTB auction in which the CBN had offered N650 billion across three maturities through the Dutch auction system.
• Primary market repayments also spiked sharply on May 21 to N634.47 billion, compared to just N8.43 billion on May 20 and N9.29 billion on May 22, pointing to a large NTB or bond maturity falling due on that date.
• This repayment injection — returning cash to investors whose securities matured — likely contributed to the high liquidity that flooded back into the system and found its way into the OMO auction subscriptions on the same day, necessitating CBN’s aggressive mop-up activity.
• Notably, the broader two-week exercise covering the first three weeks of May saw the CBN repay N4.78 trillion in two tranches across earlier OMO maturities, leaving a net OMO issuance of approximately N850 billion for that period.

The May 19 data separately recorded an OMO repayment of N2.247 trillion — a large cash injection into the system on that date — which helps explain why so much liquidity was available for the aggressive May 21 auction.

What you should know

A direct comparison between the May 21 and May 12 auctions reveals stark differences in both scale and strategy. On May 12, the CBN conducted a 35-day and 70-day OMO auction but adopted a highly selective allotment approach.

• Total subscriptions across both instruments reached N872 billion but the CBN accepted only N116 billion.
• On the 35-day bill specifically, just N25 billion was allotted out of N761 billion subscribed.
• By contrast, the May 21 auction saw the CBN accept 100% of all subscriptions received — a complete reversal of posture.
• In terms of net sales, the gap between the two auctions is enormous: N116 billion accepted on May 12 versus N3.692 trillion on May 21, a difference of approximately 3,083% — or roughly 31.8 times more liquidity absorbed in a single day just nine days later.
• Total subscriptions were also markedly higher on May 21 (N3.692 trillion) versus May 12 (N872 billion) — a jump of 323%, reflecting both the larger offer size and the growing investor appetite for OMO paper fuelled by maturing instruments returning cash to the market.
• Nigeria’s 2026 budget carries a deficit of N20.12 trillion, with over 70% expected to be funded through domestic borrowing — pushing interest rates upward and increasing borrowing costs, potentially crowding out private sector credit.
• The CBN’s willingness to absorb nearly N3.7 trillion in a single session demonstrates both the scale of system liquidity and the determination of monetary authorities to prevent that liquidity from stoking inflation or pressuring the naira.

Governor Olayemi Cardoso’s CBN has increasingly leaned on OMO bills as the instrument of choice for managing excess banking system liquidity, with cumulative OMO sales within the first four months of 2026 reaching approximately N30.12 trillion.