You'll find a lot of banks using it. A lot of traders. The amount of custom excel spreadsheets used for trades and predictions is scary
Partly True. I have worked with Traders and Analysts also. I find it quite impressive the way they start with a relatively simple spreadsheet and then improve it over time to settle down with fairly complicated analytics templates in Excel / VBA that they use to carry out sophisticated trading strategies.
There isn't anything "scary". One reason they love Excel / VBA is because most Market Data Vendors such as Bloomberg and Reuters provide simple-to-implement DDE and VB Functions that the Traders can incorporate into their spreadsheets to analyze volume, liquidity etc of their portfolios fairly quickly and accurately. Also, by design, Excel can be set to recalculate formulas and cell values automatically when something changes. This is especially useful if they link to live prices in say, a benchmark column.
The problem arises when the data has to be shared, and you end up with multiple analytics spreadsheets on shared network drive and they are not sure which one is the latest.