Purpose- This study investigates how multinational stablecoin adoption reshapes market liquidity and cross-border financial integrationacross advanced and emerging economies, with particular attention to financially constrained and high-volatility jurisdictions. It examineswhether stablecoins constitute a structural layer of global liquidity provision and market linkage or primarily reinforce speculative and cyclicaldynamics in digital asset markets, and identifies regulatory and macro-financial conditions under which stablecoin-driven integrationenhances resilience versus amplifying vulnerabilities.Methodology- The analysis uses a balanced monthly panel of 156 countries from January 2024 to July 2025, combining high-frequency on-chain transaction data for major stablecoins with market microstructure indicators and macroeconomic controls. Country- and time-fixedeffects regressions and dynamic panel estimators are complemented by network analysis of cross-border flows and event studies aroundkey regulatory and macroeconomic shocks. Liquidity is measured via bid-ask spreads, depth, turnover, and realized volatility, while financialintegration is proxied by cross-border flow ratios and co-movement between local and global prices.Findings- Higher stablecoin usage—through greater transaction volumes and wallet adoption—is linked to narrower spreads, deeper orderbooks, and higher turnover, signaling improved liquidity in emerging markets with currency or capital constraints. Network analysis highlightsnew digital liquidity hubs and denser cross-border ties, while event studies show regulatory or macro shocks cause brief fragmentation beforeflows re-route and partially reintegrate. Effects are strongest in open or moderately regulated economies with high demand for synthetichard-currency assets.Conclusion- The evidence indicates that stablecoins have become a durable component of the global financial architecture, enhancingliquidity and integration while concentrating operational and regulatory risks in a limited set of platforms and jurisdictions. The paperhighlights the need for coordinated supervisory frameworks, real-time digital monitoring infrastructures, and improved data transparency,and calls for further research on off-chain linkages, user heterogeneity, and systemic risk transmission in a stablecoin-centric environment.