Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_47308 ( "Rank" real, "Rank Forbes 2000" real, "Name" text, "Headquarters" text, "Revenue (Bn.$)" real, "Profit (Bn.$)" real, "Assets (Bn.$)" real, "Market value (Bn.$)" real, "Industry" text )

### Question ###
What is the sum of revenue for the banking industry with a Forbes 2000 rank under 53?

### Accurate SQL ###

SELECT SUM("Revenue (Bn.$)") FROM table_47308 WHERE "Industry" = 'banking' AND "Rank Forbes 2000" < '53'