BSE and Nifty

What moves BSE share values? BSE value increased like crazy since last year but I don't see a direct correlation of it with any news impacting (apart from the pre election hype) or Nifty rise and fall, recently it dropped to 5k back to 5700 then now 5300 I cannot make any correlation with Nifty or any other factor directly triggering BSE values. I can understand fed rate cut might trigger the finance segment prices , IT will get high but understanding BSE's trend is hard for me.Request if anyone can shed some knowledge. PS - very new to shares and still in learning phase.