Investor, Speculator, Gambler

Investor, Speculator, Gambler, Trader, Arbitrageur, Scalper, Fund Manager,

Let's see the definitions.
As defined by Wikipedia.
 
- An investor is a party that makes an investment into one or more categories of assets --- equity, debt securities, real estate, currency, commodity, derivatives such as put and call options, etc. --- with the objective of making a profit.

- In finance, speculation is a financial action that does not promise safety of the initial investment along with the return on the principal sum.

- Gambling is the wagering of money or something of material value (referred to as "the stakes") on an event with an uncertain outcome with the primary intent of winning additional money and/or material goods.

- In finance, a trader is someone who buys and sells financial instruments such as stocks, bonds, commodities, and derivatives.  (A day trader is a trader who buys and sells financial instruments (e.g. stocks, options, futures, derivatives, currencies) within the same trading day such that all positions will usually be closed before the market close of the trading day.)