affecting) underpricing shares PT. BRI Tbk. Variables that use in this study are Initial Return (IR), SBI rate, inflation and … Return (IR), SBI rate(t-1), inflation and exchange rate Rp/USD from January 2006 until December 2008. The method used is … coefficient 0.79 or 79%, which means that the value of SBI(t-1). rate, inflation and exchange rate Rp/USD can explain the initial …