Got it and really appreciate it. I have two clients . One has S Corp and the other one (sole-prop) should apparently file schedule C based on IRS : Topic No. 429 Traders in Securities (Information for Form 1040 or 1040-SR Filers)

Owner S Corp wants to shift his activity of stock trading to his S Corp but to be honest I am confused regarding 3115 form since traders are required to file a form 3115 but his S Corp has other activities like import and export which has already hybrid accounting method. 

How about if someone wants to open his/her business (new) with S Corp type also wants to be a day trader?

The individual one acts like sole-prop should he file 3115 as well?