Abstarct: Hawala networks, both formal and informal, are among the most significant channels for transnational financial transfers in developing economies. However, the macroeconomic literature has yet to fully integrate these networks into its analytical frxameworks. The Arbaeen phenomenon—as one of the largest transnational human gatherings, involving the movement of millions of pilgrims and substantial financial transfers—provides a unique setting for studying the effects of hawala networks on macroeconomic variables. This research aims to analyze the effects of hawala networks on economic growth, exchange rate volatility, and the balance of payments, with an emphasis on the Arbaeen experience. This study employs a sequential explanatory mixed-methods design. Using real time-series data for the Iranian economy (96 quarterly observations for the period 2000–2023) and baxsed on statistical patterns derived from official reports, ARDL models (for economic growth and the balance of payments) and a GARCH-regression model (for exchange rate volatility) were estimated. To estimate informal hawala flows, a strategy of proxy variables, principal component analysis, and composite index calibration was employed. In the qualitative phase, documentary and institutional analysis was used to understand the transmission mechanisms. The model estimation results demonstrated that the proposed models possess the necessary technical capability to identify the hypothesized relationships. In the first model, the Arbaeen financial shock showed a positive and statistically significant effect on quarterly economic growth (coefficient = 0.623, p = 0.034), with the effect primarily transmitted through the services sector. In the second model, the occurrence of Arbaeen was associated with a 42.5 percent increase in exchange rate volatility relative to the mean (coefficient = 0.034, p = 0.006), and this effect intensified during the post-sanctions period. In the third model, formal and informal hawala networks exhibited distinct effects on the current account balance: formal flows were associated with an improvement (+0.345), while informal flows were associated with a deterioration (−0.567), with the Wald test confirming a statistically significant difference between the two (p = 0.004). Robustness checks confirmed the stability of these results against changes in variable definitions and calibration methods. The findings are consistent with Keynesian aggregate demand theory, North's institutional analysis, and the World Bank's literature on remittances. Policy implications include forward-looking exchange rate management during Arbaeen, strengthening formal payment infrastructure along pilgrimage routes, designing an Arbaeen satellite account within the national accounts system, and enhancing institutional coordination among relevant authorities.