You should understand the US rules applicable to trades in security or security-like instrument in markets governed by US law before undertaking any such trading. US law could apply to trading in US markets irrespective of the law applicable in your home jurisdiction.
Many (but by no means all) stocks, bonds and options are listed and traded on US stock exchanges. NASDAQ, which used to be an OTC market among dealers, has now also become a US exchange. For exchange-listed stocks, bonds and options, each exchange promulgates rules that supplement the rules of the US Securities & Exchange Commission ("SEC") for the protection of individuals and institutions trading in the securities listed on the exchange.
OTC trading among dealers can continue in exchange-listed instruments and in instruments that are not exchange-listed at all. For securities that are not listed on any exchange, trading can continue through the OTC bulletin board or through the inter-dealer “pink sheets” that carry representative (not actual) dealer quotes. These facilities are outside of NASDAQ.
Options on securities are subject to SEC rules and the rules of any securities exchange on which the options are listed. Options on futures contracts on commodities like wheat or gold are governed by rules of the US Commodity Futures Trading Commission ("CFTC"). There are also commercial options, like options on real estate, that are governed neither by SEC nor CFTC rules.
Whether you are intending to trade in US exchange-listed securities, OTC securities or derivatives (such as Options or Futures), you should understand the particular rules that govern the market in which you are intending trade. An investment in any of these instruments tends to increase the risk and the nature of markets in derivatives tends to increase the risk even further.
Market makers of OTC bulletin board are unable to use electronic means to interact with other dealers to execute trades. They must manually interact with the market, i.e. use standard phone lines to communicate with other dealers to execute trades. This may cause delays in the time it takes to interact with the market place. This, if coupled with increase in trade volume, may lead to wide price fluctuation in OTC bulletin board securities as well as lengthy delays in execution time. You should exercise extreme caution when placing market orders and fully understand the risks associated with trading in OTC bulletin board.
Market data such as quotes, volume and market size may or may not be as up-to-date as expected with NASDAQ or listed securities.
As there may be far fewer market makers participating in OTC securities markets, the liquidity in that security may be significantly less than those in listed markets. As such, you may receive a partial execution or the order may not be executed at all. Additionally, the price received on a market order may be significantly different from the price quoted at the time of order entry. When fewer shares of a given security are being traded, larger spreads between bid and ask prices and volatile swings in price may result. In some cases, the liquidation of a position in an OTC security may not be possible within a reasonable period of time.
Issuers of OTC securities have no duty to provide any information to investors, maintain registration with the SEC or provide regular reports to investors.