As some sibling comments suggest, not all finance is created the same. Trading systems often use floating point, but banking/accounting systems used fixed point

As some sibling comments suggest, not all finance is created the same. Trading systems often use floating point, but banking/accounting systems used fixed point. The key is whether your system needs to tally up your monies into a known quantity and ensure it is all accounted for. If you summed up the transactions across a number of customer accounts at a bank for instance, it's critical that they all net out.