What is Leverage?
A multiplier on your deposit that lets you control a position larger than your capital — 1:30 means $30 of position per $1 of margin.
Leverage in forex is the broker's loan that lets you trade positions larger than your deposit. At 1:30 leverage, $1 of margin supports $30 of position size. At 1:100, $1 supports $100. At 1:500, $1 supports $500.
Leverage does NOT change the P&L of the position. A 100-pip move on one EURUSD lot is $1,000 of profit (or loss), regardless of whether you used 1:30 or 1:1000 leverage. What changes is the margin requirement — and how quickly a stop-loss converts to liquidation.
Regulator caps: EU (CySEC, FCA) and Australia (ASIC) cap retail leverage at 1:30 on majors, 1:20 on minors, 1:2 on crypto. US (CFTC + NFA) caps at 1:50. Singapore (MAS) at 1:20. Japan (JFSA) at 1:25. Offshore (FSA Seychelles, FSC Mauritius, VFSC) goes up to 1:1000.