Investing in bitcoin was risk in the past when people were new to it and were not having enough faith in it as at that point they had fear of loosing their money in it but now after looking the growth and success of bitcoins I don't think there is any risk of investing money into it.
Now the risk with bitcoin have decreased much, but at the same finding a trusted investment platform is simply a hard task for the users. Because these days understanding the potential of bitcoin and the user acceptance lot have involved into scam attempts and get the people's money in the name of investment. So this need to be overcome while making a good bitcoin investment.