I think the biggest difficulty in the above sentence is the word positions. This is not a verb, but a noun; The meaning is not ordinary "position", but "position" in financial terms. The basic structure of the whole sentence is that the meta position ... increases to ... from ... according to. ...

The translation is as follows:

According to the data released by the Bank of China on Monday, by the end of 1, the RMB positions accumulated by financial institutions due to buying foreign exchange had increased to 15.5 trillion yuan, an increase of 14 10 billion yuan from last month.