There is a lot of symbolism in this short story. The man in the story has that will make him wealthy and well known. He has spent countless hours on this project and is just about to sit down and work it all out into a proposal.
His wife is leaving the house, alone, to go to a movie. She would really like to have him go with her, but he's intent on this work project. So she leaves...and as she shuts the door, the breeze catches his paper...the only paper...that has all of his information written down on it and carries it out of the window. His efforts will be lost. His work will be for nothing. This symbolizes the fleeting nature of man's works.
The symbolism here is that life is brief and priorities must be established. He risks everything for this piece of paper. What is this piece of paper if it costs him his love or his life?
She is alone, and he is alone. Each of them are doing different activities, but they each are alone. This is a significant symbol in this story, because each human faces trials of fear and courage totally alone no matter who may be present. Every human must face death alone.
As a psychological story, the vertigo the man experiences when he sees the ground is quite intense. It symbolizes how his dream is slipping away and that he must maintain his balance in order to live. Once he grasps the paper and gets it between his teeth, he is unable to move. Again, paralyzed by fear, he is stuck. This man is stuck in his life as a grocery boy, and he's probably one of those people who is afraid to make a move without everything being just right and totally perfect. This is a type of self-sabotage. Being out on the ledge symbolizes where he is in his life. He is unknown to the world, just another grocery clerk. But his desire is fame.
When he is trying desperately to return to his apartment, he is literally locked out of his own home. Unsafe and on a window-ledge he can see inside his home, but cannot get in. If he had gone out with his wife, he would not be home, but he would not be having a near-death experience either.
The yellow paper symbolizes desires and dreams that must be let go in order to have what really counts in life. He does let this go the second time after what it almost cost him the first time.