I have start a new online business and do seo for that site. First my site was stay out of 100 pages when search by some keywords in Google. Day by day increase traffic and came Google first page. But past week I saw my site in Google second pages. Are anybody know what happen?

The Google algorithm changes constantly ever so slightly. If your site is new, then it could be that your link profile isn't stable enough to warrant yur position. You need to build up a solid link profile, varying the anchor text.

As an aside, did your traffic drop along with your rankings? Not everyone sees the same results of course, as it it depends on many factors.

The reasons for that may be various and you may get the answer to your question only after detailed analysis of your SEO campaign.

Perhaps, at the beginning you had been new to this niche, but later the competition got tougher and you were squeezed from the first page of search results in Google.

Maybe you were outranked by your website's competitors, cause your site is poorly optimized and you should tune it up to make it Google appealing.

Anyway. It ain't a dead end and it's possible to find a way out and get back to the top of Google search results.

Hello,

Google crawlers works on algorithms, in which he counts the links every crawling & to keep stable ranking of your website you just need to make backlinks continue.

Your competitors are doing the SEO or other promotional ways just to get higher rankings. If you want to get on top positions, continue to build links.

Yes, Your competitors are also a reason of rank down. Watch your competitor sites and compare with your own site. You will know all things what you are looking for ?

Thanks