At least you did Google in the meantime to find out the different between IV and SV.
You can be right in the direction with either of your long legs in a straddle or strangle. If the vola of the underlying, which is called SV = Statistical volatility or also known as HV = Historical Volatility , is rising slowly, the IV of the options are rising or declining slowly. The IV is the implied volatility of the options and not of the underlying. In all your past post you always asked about IV but not about SV or HV. This showed that you did not understand about what you are talking. Never mind as we all started some one some where and now you Googled at least about this specific point.
Now the next point you mention is theta, which is not interesting for you but only vega or vola of the underlying which will result in the IV of the options. Fine. Let us know when you entered the trade and how the result at the end was. Good luck.