No I never think it is safe investment because knowing how bitcoin grows there is a chance of crash on anytime that make it a risky investment but we can't deny the fact that it really attracts lots of investors that makes it a good investment indeed.
There is nothing like a safe investment, except if you are investing in your skill set.
Most investments have their own risk; the only difference is the level of the risk of every investment. Bitcoin has its own risks when compared to other investments; the best thing to just be on the safe side is to invest what you can afford to lose. Even our own currency is not safe.
I think there is no other safe way to invest rather than the bitcoin, because the bitcoin have very strong security even no one can see your account information. Bitcoin give you the freedom of invest and give you the rights to get help from all over the world with a very safe way and provide you a very safe transfer of the bitcoin itself. So it can be said that bitcoin is ever safe for any investment.