Margin call calculators break when Asian and Western brokers define maintenance ratio differently

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A developer building a margin call calculator for leveraged stock positions discovered that Asian brokers (Taiwan, China, South Korea) and Western brokers (US, EU) use fundamentally different formulas to define the maintenance margin ratio. Asian brokers express it as total position value divided by the outstanding loan, typically around 166%, while Western brokers calculate equity as a percentage of total position value, typically around 30-40%. Despite describing identical account risk, the two ratios are mathematically distinct, and applying the wrong formula produces an incorrect liquidation price. The calculator addresses this by branching logic based on locale, automatically switching both the formula and the default ratio threshold accordingly. The tool's core function is to rearrange each ratio formula algebraically to solve for the exact price at which a margin call would be triggered, sparing users the manual calculation during stressful market conditions.

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