Does using the information on the document mean whoever misplaced is going to lose something? Probably not. My point is, the OP's case and your example about the wallet are not the same.
PS: if I were the OP I would try to return or destroy them.
PS: if I were the OP I would try to return or destroy them.
Depending on information, how it is used, etc. I can imagine him losing his job.
If the OP has found information that will genuinely allow him to place stock trades at an advantage to the rest of the market then some people are going to lose something.
Conversely, doing the wrong thing probably means that the 'unintended consequences' are bad - getting caught etc.
You could take the documents and through thinking of 'I have struck gold' and nothing else, walk out of the cab and into the on-coming bus, to go under it and be rescued by the paramedics.
However, what I think you are getting at has been discussed regarding music.
Imagine finding a USB stick, making a perfect copy of it. When you get home you find that it contains the latest and as yet unreleased album by your favourite artist. Being good you don't post it onto youtube or even let your mates have a copy. However, even then the record label would deem you a pirate, if they found out. But we have had that argument.
Or...
The financial scenario: you find documents that Google are to make a cash bid for Facebook next week. You sell your mother and buy lots of shares in Facebook. The bid happens and you get to sell your shares, buy your mother back and make a tidy profit. Seems simple, victimless crime!
However, the documents could have been planted there (and elsewhere) by someone in the city with lots of shares to sell and wanting to 'secretly tip' the market so they profit. In this case you lose out on your investment and cannot buy your mother back.
Or Sergei and Brin find they have lost their documents in the back of the cab, see it as an omen, and don't go ahead with the bid.
However, if you did try and return the documents and were successfully able to do so, they might give you a T-shirt and a pat on the back for being good. They might even give you a job.
Here is a joyful parable:
The Parable of the Flowers
Believing in God is to believe in God's presence and uniqueness. This belief saves the person from meaninglessness and from being errant. Assuming that lies would make a person happy is to go after a dream that will never come true. Reality is God's consent.
In old times, there was a sagacious emperor, and his people loved him. But the emperor was enduring an absence; he did not have a son or a daughter. After a while, the emperor decided to adopt a child.
Public criers shouted, "Listen to me people! On Friday our emperor will adopt a child. This child must be a ten year-old boy; our emperor will leave his throne to his foster son, and he will rest. The people who want to give their sons to the emperor should gather in front of the palace on Friday."
Before the crier finished talking, the public square in front of the palace became full of ten year-old boys.
The emperor gave flower seeds to each boy, and declared his condition: "After sowing these seeds and growing them, you should bring me a bunch of flowers. Of whose flowers that I become fond of, that boy will become my adopted son. You have three months; after this period it is our decision to gather in this same place."
Three months passed. The emperor went to the square and saw that the square was full of beautiful flowers with different colors. The boys who had taken the seeds were waiting for the happy moment.
The emperor looked attentively at the boys while passing near them without stopping.
At another corner stood a boy crying who had no flowers in his hands. The emperor went near the boy, and stopped. He asks:
"Why are you crying?"
The boy spoke of his trouble:
"My emperor, the seeds that your Excellency has given me did not grow despite my efforts. I tried everything, but in vain. I am weeping because you will not adopt me since I do not have any flowers."
The emperor replied, "Do not cry because of that, because I will adopt you as my son. Your seeds did not become flowers because I boiled them before giving them to you. These people who have brought flowers think that they can deceive me. Their flowers are not from my seeds. They found them somewhere else" said the emperor and hugged the boy.
"You told me the truth; you did not lie to me. Listen carefully, it is the person who accepts the truth, not the liar, who will become happy in the end."
An interesting moral for a situation based on finding information.
I'm sympathetic to your conclusion, but this seems spurious reasoning. Why is it more likely that you'd be hit by a bus thinking about how you're going to take advantage of the information than hit by a bus thinking about how you're going to get the documents back to the person?
Unbalanced positive ramifications are most likely to be social.
Most people that step out into the road in front of me on my commute are doing the 'ipod shuffle', distracted by text or talking about what they are going to have for dinner. So it isn't as if they are distracted by anything really significant and in some way that is where the danger is - an assumption they can multi-task whilst crossing the road. If they were interrupted by someone calling to say they had won the lottery etc. then they probably would stop in their tracks and not attempt to cross the road there and then.
When I found the wallet the other day I did think whether anyone had seen me and I did think about whether there was CCTV and whether I could get caught had I just taken the money. However I quickly decided that I was going to try and return the wallet. I made a few paces up the road before turning back and going to the corner shop to see if they recognised the guy in the travelcard photo. I was distracted, no question about it, and, had I needed to have crossed a road then I might not have had my wits about me.
So, what would have happened had I decided to take the money? Rather than think about whether I had been seen I would have had to actually check every bit of street furniture for CCTV and every window overlooking me. I would have had to surreptitiously put the wallet in a pocket and gone through the thought process of where I was to dispose of it etc. Maybe, as a result, I would have been extra careful on the road.
However, I believe that cheating/stealing/doing wrong poses an abnormal and detrimental strain to thinking. By analogy, one of my Scrabble playing friends has this habit of cheating. He is a journalist with a considerable vocabulary, with pride to match. Therefore he has to win. However, the rest of us know that he sometimes does things with the letters bag and sometimes we choose to turn a blind eye. The added strain of cheating and not getting caught affects his game meaning that he puts himself at a competitive disadvantage. He can have a rack full of 'Q's and 'Z's and miss a seven letter triple word score word like 'quizzed' because he is more focused on trying to get a 'U' from the bag when there is a perfectly good one on the board already.
To conclude, it is the element of deceit.
And that's what makes this tricky, because stock market situations are so unlike ordinary life. Is there deceit?
The OP has the option of returning the papers as soon as possible, and informing the people he returns them to about his stock market plans. He could in fact tell everyone he meets about his stock market plans and still be capable of a tidy profit.
There's something uncomfortable about the situation, but it's really hard to pin down what it is, and I don't think there's any dishonesty involved.