Buenos Aires — Argentina’s peso edged up on Monday and the local Merval stock index rallied after centre-left Alberto Fernandez clenched victory over incumbent Mauricio Macri in the presidential election and the central bank clamped down on dollar purchases.

The peso was 0.02% stronger in morning trade at 59.98 per dollar, traders said. However, Argentina’s black market peso split away, weakening 1.95% to 77 per dollar, a record low. Another often-cited price, known as a blue-chip swap, held stable at 81.5 pesos per dollar...