She was building a company that instantly exchanged any currency for any currency, including digital.

Her design threatened the world's currency owners, because it gave people an escape from being locked into a single currency.  For example, it would allow a person in Singapore to live their life using the currency of their choice (gold, bitcoin, yen, usd, british pound, canadian dollar, etc.) without ever touching or holding a Singapore dollar, and having total freedom to transact with anyone and everyone.

That's why she was killed.