bitburner-src/doc/source/basicgameplay/stockmarket.rst

.. _gameplay_stock_market:

Stock Market
============
The Stock Market refers to the World Stock Exchange (WSE), through which you can
buy and sell stocks in order to make money.

The WSE can be found in the 'City' tab, and is accessible in every city.

Fundamentals
------------
The Stock Market is not as simple as "buy at price X and sell at price Y". The following
are several fundamental concepts you need to understand about the stock market.

.. note:: For those that have experience with finance/trading/investing, please be aware
          that the game's stock market does not function exactly like it does in the real
          world. So these concepts below should seem similar, but won't be exactly the same.

Positions: Long vs Short
^^^^^^^^^^^^^^^^^^^^^^^^
When making a transaction on the stock market, there are two types of positions:
Long and Short. A Long position is the typical scenario where you buy a stock and
earn a profit if the price of that stock increases. Meanwhile, a Short position
is the exact opposite. In a Short position you purchase shares of a stock and
earn a profit if the price of that stock decreases. This is also called 'shorting'
a stock.

.. note:: Shorting stocks is not available immediately, and must be unlocked later in the
          game.

.. _gameplay_stock_market_spread:

Spread (Bid Price & Ask Price)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The **bid price** is the maximum price at which someone will buy a stock on the
stock market.

The **ask price** is the minimum price that a seller is willing to receive for a stock
on the stock market

The ask price will always be higher than the bid price (This is because if a seller
is willing to receive less than the bid price, that transaction is guaranteed to
happen). The difference between the bid and ask price is known as the **spread**.
A stock's "price" will be the average of the bid and ask price.

The bid and ask price are important because these are the prices at which a
transaction actually occurs. If you purchase a stock in the long position, the cost
of your purchase depends on that stock's ask price. If you then try to sell that
stock (still in the long position), the price at which you sell is the stock's
bid price. Note that this is reversed for a short position. Purchasing a stock
in the short position will occur at the stock's bid price, and selling a stock
in the short position will occur at the stock's ask price.

.. _gameplay_stock_market_spread_price_movement:

Transactions Influencing Stock Price
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Buying or selling a large number of shares of a stock will influence that stock's price.

Buying a stock in the long position will cause that stock's price to
increase. Selling a stock in the long position will cause the stock's price to decrease.
The reverse occurs for the short position. The effect of this depends on how many shares
are being transacted. More shares will have a bigger effect on the stock price. If
only a small number of shares are being transacted, the stock price may not be affected.

Note that this "influencing" of the stock price **can happen in the middle of a transaction**.
For example, assume you are selling 1m shares of a stock. That stock's bid price
is currently $100. However, selling 100k shares of the stock causes its price to drop
by 1%. This means that for your transaction of 1m shares, the first 100k shares will be
sold at $100. Then the next 100k shares will be sold at $99. Then the next 100k shares will
be sold at $98.01, and so on.

This is an important concept to keep in mind if you are trying to purchase/sell a
large number of shares, as **it can negatively affect your profits**.

.. note:: On the Stock Market UI, the displayed profit of a position does not take
          this "influencing" into account.

Transactions Influencing Stock Forecast
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
In addition to influencing stock price, buying or selling a large number of shares
of a stock will also influence that stock's "forecast". The forecast is the likelihood
that the stock will increase or decrease in price. The magnitude of this effect depends
on the number of shares being transacted. More shares will have a bigger effect on the
stock forecast.

.. _gameplay_stock_market_order_types:

Order Types
^^^^^^^^^^^
There are three different types of orders you can make to buy or sell stocks on the exchange:
Market Order, Limit Order, and Stop Order.

.. note:: Limit Orders and Stop Orders are not available immediately, and must be unlocked
          later in the game.

When you place a Market Order to buy or sell a stock, the order executes immediately at
whatever the current price of the stock is. For example if you choose to short a stock
with 5000 shares using a Market Order, you immediately purchase those 5000 shares in a
Short position at whatever the current market price is for that stock.

A Limit Order is an order that only executes under certain conditions. A Limit Order is
used to buy or sell a stock at a specified price or better. For example, lets say you
purchased a Long position of 100 shares of some stock at a price of $10 per share. You
can place a Limit Order to sell those 100 shares at $50 or better. The Limit Order will
execute when the price of the stock reaches a value of $50 or higher.

A Stop Order is the opposite of a Limit Order. It is used to buy or sell a stock at a
specified price (before the price gets 'worse'). For example, lets say you purchased a
Short position of 100 shares of some stock at a price of $100 per share. The current
price of the stock is $80 (a profit of $20 per share). You can place a Stop Order to
sell the Short position if the stock's price reaches $90 or higher. This can be used
to lock in your profits and limit any losses.

Here is a summary of how each order works and when they execute:

**In a LONG Position:**

A Limit Order to buy will execute if the stock's price <= order's price

A Limit Order to sell will execute if the stock's price >= order's price

A Stop Order to buy will execute if the stock's price >= order's price

A Stop Order to sell will execute if the stock's price <= order's price

**In a SHORT Position:**

A Limit Order to buy will execute if the stock's price >= order's price

A Limit Order to sell will execute if the stock's price <= order's price

A Stop Order to buy will execute if the stock's price <= order's price

A Stop Order to sell will execute if the stock's price >= order's price.

.. note:: Limit and Stop orders do **not** take into account the fact that
          transactions can influence a stock's price. If a stock's price
          changes mid-transaction, a limit/stop order will continue to execute
          even if its conditions are no longer met. 

Automating the Stock Market
---------------------------
You can write scripts to perform automatic and algorithmic trading on the Stock Market.
See :ref:`netscript_tixapi` for more details.

Under the Hood
--------------
Stock prices are updated very ~6 seconds.

Whether a stock's price moves up or down is determined by RNG. However,
stocks have properties that can influence the way their price moves. These properties
are hidden, although some of them can be made visible by purchasing the
Four Sigma (4S) Market Data upgrade. Some examples of these properties are:

* Volatility
* Likelihood of increasing or decreasing
* How easily a stock's price/forecast is influenced by transactions
* Spread percentage
* Maximum price (not a real maximum, more of a "soft cap")

Each stock has its own unique values for these properties.

Offline Progression
-------------------
The Stock Market does not change or process anything while the game has closed.
However, it does accumulate time when offline. This accumulated time allows
the stock market to run 50% faster when the game is opened again. This means
that stock prices will update every ~4 seconds instead of 6.