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Which transactions look suspicious? Which users show abnormal transaction behavior? Are there unusual bursts of transactions? Are multiple users using the same device? Are certain receivers receiving money from unusually many users? Are there unusual high-value transactions? Do suspicious transactions cluster around particular times? How much transaction value is potentially exposed? Which suspicious patterns deserve investigation?
Which users transact unusually frequently? Which receivers receive money from many different users? Which devices are associated with many users? Are there suspicious bursts within minutes? Which transactions combine multiple suspicious signals? Can we identify the hidden fraud without looking at the ground truth?