Put all eggs in one basket

Put all eggs in one basket - to make everything dependent on only one thing.

Example - "I advise you to diversify and not put all eggs in one basket"

Image - http://static1.squarespace.com/static/54e476b6e4b02a41587ac793/5500d1c1e4b073563bd4f55b/5500d1c2e4b073563bd4f664/1426117097698/bigstock-All-Eggs-In-One-Basket-Cartoon-75053410.jpg