Traffic loss by 20% - Hit by Google Update??

Hello everyone,

One of my company's website (Niche - Tech) has lost almost 20% of its daily traffic. I was thinking that it happens because of Google's latest algorithm update "Product Review", but when I checked the Google Analytics "The post whose traffic has been down was not a product review post", all of these are "How-to" based post.

Now I'm not able to figure out why this happened and how to recover from this. Can someone help me in this, how can I recover my lost traffic or is there any google update, that hits the website.

Looking for your precious help

Thanks in advance :)