Rupee set to climb amid arbitrage unwinding prompted by RBI position limits

RBI's Bold Move to Rein in Bank Positions

The Reserve Bank of India dropped a significant announcement late last Friday, shaking up the forex market just as traders were winding down for the weekend. The central bank introduced strict limits on banks' open positions in the onshore currency market, capping them at $100 million per authorized dealer at the end of each trading day. This is a sharp departure from the previous rules, which allowed positions up to 25% of a bank's capital and permitted netting across onshore and offshore markets.

These new regulations, set to kick in on April 10, zero in on a common arbitrage strategy that's been popular among banks. In this trade, institutions buy US dollars against the rupee in the domestic market while selling them in offshore non-deliverable forwards, or NDFs, to pocket the spread. Market estimates peg the total size of these positions at $30-40 billion across all banks. With the cap now focusing solely on gross onshore holdings, banks face pressure to unwind these bets quickly, which could flood the market with dollar sales.

The immediate market reaction was telling. On Monday, the rupee opened sharply higher at 93.58 against the dollar, a notable jump from Friday's close of 94.80. Traders anticipate further gains, potentially pushing the pair toward 93.50-94.50 in the short term, marking a relief rally of 70-100 paise from recent lows. This move comes amid broader pressures on the currency, including a 10% depreciation over the fiscal year so far, exacerbated by geopolitical tensions in West Asia and stubbornly high crude oil prices.

Unwinding Arbitrage: A Boost for the Rupee

As banks scramble to comply, the unwinding process is expected to strengthen the rupee tactically. Selling dollars onshore to square positions will naturally drive down the USD/INR rate, making the local currency appreciate. At the same time, buying back offshore NDFs could widen the gap between onshore and offshore rates, along with forward points. This compression might also ease implied yields in the domestic market as liquidity adjusts.

However, this isn't without costs. Banks could book mark-to-market losses, with some estimates suggesting potential hits of up to ₹4,000 crore if the onshore-offshore spread stretches to a full rupee. There were reports of banks lobbying the RBI over the weekend for leniency, perhaps applying the cap only to new positions post-April 10. For now, though, the directive stands firm, giving the central bank more room to manage volatility without flooding the system with interventions that could spill over into the bond market.

"This directive effectively hands the RBI an extra $30-35 billion in firepower to defend the rupee without stirring up domestic liquidity or bond yields, though it's not great news for bonds," a senior forex trader noted, highlighting the nuanced impact on markets.

Broader Context and Future Outlook

The RBI's forward book adds another layer to this story. Reports indicate it has swelled to a net short position exceeding $100 billion by March, up from $67 billion in January, as the bank sells dollars forward to prop up the rupee. Spot interventions have been more modest at around $10 billion, but usable reserves remain substantial at roughly $570 billion, excluding gold. Still, accounting for the forward commitments paints a slightly less rosy picture of defensive capacity.

Looking ahead, any rupee strength from this unwinding could prove short-lived. Persistent crude oil spikes tied to Gulf conflicts might yank the currency back toward 96-97 per dollar by April. Even in an optimistic scenario with de-escalation, the RBI might intervene to limit appreciation around 92-92.50 levels, rebuilding reserves in the process. Government borrowing plans, dialed back to 51% of the budgeted ₹16.1 trillion for the first half of FY27, offer mild support by easing supply pressures.

For investors and exporters, this episode underscores the RBI's proactive stance in stabilizing the rupee amid external shocks. The position limits not only curb speculative excesses but also enhance the central bank's toolkit for future interventions. As markets digest these changes, the focus shifts to how smoothly banks exit their trades and whether the RBI tweaks the rules further. In essence, the rupee's climb reflects regulatory muscle flexing, but sustaining it will hinge on global oil dynamics and policy finesse.

This development signals a tactical rupee uptick from position unwinding under RBI's $100 million onshore cap, amid arbitrage trades worth $30-40 billion, though gains may fade with oil pressures and forward book strains.