Twitter

Interacting with a Trading Simulation over Twitter

Contents

• Motivation
• Implementation
  • Syntax of the commands
    • View portfolio
    • Buy a stock
    • Sell a stock
    • Offer a security for sale to a specific user
    • Accept an offer
    • Decline an offer
    • Offer a security for sale at auction
    • Bid on an auction
    • Comment on a trade
    • Comment and vote on a trade
• Design considerations

Motivation

Twitter is a service that is already widely used by many people, so there is a lower threshold of learning and discovery to play a game over Twitter than to use a dedicated website. It is not expected that the Twitter interface will duplicate all features of the website; rather users will be able to perform their most common tasks from an interface they are familiar with.

The bulk of the proposal is a syntax that represents the operations of the game. This syntax could integrate into any system that allows sending brief messages from named accounts. However, since Twitter is already well integrated this extra flexibility may be unnecessary.

Implementation

The game has an account, tentatively named pitfail, and will listen for user tweets sent to @pitfail.

Users must explicitly associate their Twitter accounts with their PitFail accounts. Once Twitter name joe is associated with PitFail account joe26, tweets from joe26 will be interpreted as belonging to account joe.

The program may respond to tweets that require a response by sending tweets back to users.

Syntax of the commands

View portfolio

@pitfail #portfolio

PitFail will respond with assets and liabilities in a human-readable form.

Buy a stock

@pitfail #buy 100 shares of HP

or:

@pitfail #buy HP * 100

(See Products # A language for securities)

or:

@pitfail #buy $250 of HP

PitFail will respond with an ACK if successful, or an error if the trade failed.

Sell a stock

@pitfail #sell 100 shares of HP

@pitfail #sell HP * 100

@pitfail #sell $250 of HP

Offer a security for sale to a specific user

@pitfail @joe #want 100 shares of HP for $250?

See Syntax for securities

Accept an offer

@pitfail @laura #yes

This has an obvious ambiguity if @laura has made @joe more than one offer. Because that ambiguity could be used to trick @joe, it should not be allowed to make more than one outstanding offer to the same user from the same user.

Decline an offer

@pitfail @laura #no

Offer a security for sale at auction

@pitfail #auction 100 shares of HP

When an auction is started it is assigned an id, which is a unique, short string. The ID can be used when bidding on the auction.

Bid on an auction

@pitfail #bid $15 on #ae7

Comment on a trade

@pitfail @joe Are you serious?

Comment and vote on a trade

@pitfail @joe Are you serious? #down

@pitfail @joe Dammn... #up

These may be ambiguous, but it's not a big deal since little money is at stake. If the user wants to dig up an old trade and comment on it, they can use the ID assigned by pitfail:

@pitfail @joe Are you serious? #cc2f #down

Design considerations

• Operative words are given #tags so that users don't accidentally make trades when just trying to discuss them.
• When offering a security to another user, the role of the @pitfail account is minimized -- it's still there watching so it can actually make the trade, but the users feel as if they are just responding to each other. It makes it feel more like a real trade.