This question asks for feedback on a specific game-mechanic. Since there is not one right feedback on a game mechanic, I tried to provide enough context and guidelines to still make it possible for users to rate answers and to accept an answer as the best answer (following these criteria from Writer.SE's meta website). Please comment if you have any suggestions on how I could improve the question in that regard.

So, let's begin with the game itself and some of its elements which are relevant for this question.

Context

I'm working on a satirical, text-based multiplayer adventure and role-playing game set in modern-day London. The game resolves around the concept of sin and features a myriad of (venomous) allusions to all the things that go wrong in this world.

Players can choose between character classes like bullshit artist (consultant), bankster, lawyer, mobster, celebrity, politician, etc. In order to complete the game, the player has to live so sinfully with regard to any of the seven deadly sins that a demon is willing to offer them a contract of sponsorship. On their quest to live a sinful live, characters explore more and more locations of modern-day London (on a GoogleMap), fight "monsters" like insurance sales agents or Jehovah's Witnesses, and complete quests, like building a PowerPoint presentation out of marketing buzz words or keeping up a number of substance abuse effects in order to progress on the gluttony path. Battles are turn based with both combatants having a deck of cards, with which they try to make their enemy give in to temptations of all sorts. Tempted enemies sometimes become contacts (an item drop mechanic), which can be exploited for various benefits, depending on their area of influence (finance, underworld, bureaucracy, etc.), level of influence, and kind of sway that the player has over them (bribed, seduced, threatened, etc.) Once a contract has been exploited, the player loses that contact.

Most actions require turns. Turns are limited, but refill each day.

Criteria

A number of peripheral game mechanics are supposed to

• represent real world abuses and mischief in a humorous way
• integrate real world data and events to strengthen the feeling of relevance of the game's humor with regard to real world problems
• add fun ways of interacting with other players
• add ways for players to express themselves through game-play

Market manipulation is one such peripheral game mechanic and should fulfill all of these goals.

Market manipulation

This is my initial design of the mechanic:

• Players can enter the London Stock Exchange (LSE) (without paying a turn)
• LSE displays the stock prices of a number of companies in industries like weapons or tobacco as well as some derivatives based on wheat and corn. The stock prices are calculated based on
  • the actual stock prices of these companies and derivatives (in real time)
  • any market manipulations that were conducted by the players
  • any market corrections of the system
• Players can buy and sell shares with cash, a resource in the game, at current in-game market value (without paying a turn).
• Players can manipulate the market, i.e. let the price of a share either rise or fall, by some amount, over a certain period of time. Manipulating the market requires
  • 1 turn
  • A contact in the financial sector (see above). The higher the level of influence of the contact, the stronger the effect of the manipulation on the stock price, and/or the shorter it takes for the manipulation to manifest itself.
  • Market manipulation also adds a crime to the player's record. (There are a multitude of ways to take care of that, but it is still another "cost" of market manipulations.)
• The system continuously corrects market manipulations by letting the in-game prices converge towards their real world counterparts at a rate of 2% of the difference between the two per hour. Because of this market correction mechanism, pushing up prices (and screwing down prices) becomes increasingly difficult the higher (lower) the price already is.
• Whenever food prices reach a certain level, in-game stories are posted about hunger catastrophes happening somewhere far, far away (maybe with links to real world news stories). Whenever a player sells a certain number of shares with a sufficiently high margin, they are mentioned in that day's in-game financial news.

Since the number of stock options is very limited, players will inevitably collide in their efforts to manipulate the market in their favor. Hopefully, it will also be a fun side-arena for guilds and covenants to fight each other.

Question(s)

• What do you think of this mechanism given the criteria for peripheral game mechanics that I specified for my game?
• Do you have any ideas how the mechanic could be improved with regard to these criteria (or otherwise)? Could it be improved to allow for more expressive game-play, or involve an allusion to some other real world madness (like short selling, leveraging, or some other banking magic)?
• Are there any game-theoretic problems with this mechanic, like maybe certain dominant individual strategies that, collectively, lead to every player profiting and thus eliminating the idea of market manipulation PVP?

Also, if you like (or dislike) this question, feel free to participate in the discussion on GDSE meta: "Should we be more lax with regard to SE's question/answer format to make game design questions possible?"