Securitisation: If a bank lends money to a company or an individual, it is called a loan. The bank is at risk if the borrower defaults and cannot service the loan. So the bank 'securitises' the loans and packages them into investments, selling them to third-party investors. The bank has now taken the risk of the loans off its books and no longer needs to set aside capital to protect against their default so it's free to grant even more dodgy loans.
Mortgage-backed securities: They're repackaged home loans that third-party investors bought. Investors are willing to buy mortgage-backed securities because it's backed by thousands of loans so the risk of default is much lower and it pays a healthy interest return.
Credit default swaps (CDS): They're essentially 'insurance policies' that protect the default of something or someone. Buyers of CDS make regular payments to a swap seller, in exchange for a payout when there is a default.
The CDS market plays a key starring role in the story of the current financial crisis. Banks in the US that granted dodgy mortgages securitised the loans and sold them to investment banks like Lehman Brothers to get the loans off their books, the latter would then buy CDS from an insurer like AIG to neutralise the risk.
The CDS market was unregulated, so AIG didn't have to put up any capital to back the swaps. It is why AIG and other swap issuers continued to issue them freely until they became a US$60 trillion market. As housing prices collapsed in the US, sellers like AIG had to make big payout they could not afford.
Collateralised debt obligations (CDO): They're like mortgage-backed securities but instead of mortgages they are mode up of different types of assets incl. commercial property and bonds.
Leveraging / Gearing: it measures the degree to which a company or an investor is using borrowed money.
Leveraging plays an important role in the financial crisis because many investment banks borrowed heavily - using their share as collateral - to invest in risky high-return securities. This is highly profitable as long as the market was rising. Instead of stumping up $100 to buy something, they would put up $10 and borrow the money. If they made money from that $100, they return on the actual money wages ($10) would be much higher.
Libor / Sibor: The London (Singapore) Interbank Overnight Rate. They refer to the rates that banks charge when they lend money to one another. Libor & Sibor have soared as banks become more cautious about lending money to one another and want a premium for doing so. But Sibor has eased in recent weeks (now 3-m Sibor is at 1.5521% and 12-m at 1.7708%).
Treasuries: These are government bonds issued by the US Treasury Dept., incl. treasury bills, treasury notes and treasury bonds. They are seen as the ultimate safe-haven investment as backed by the mighty US government.
Derivatives: These are a class of instruments that derive their value from another underlying asset, such as a company stock, allowing investors to profit from movements in the stock price without actually owning the stock. Investors can buy derivatives to take bets on anything from interest rates to the weather.
Short-selling: This is when an investor sells a financial instrument like a stock that he doesn't own, in the hope of buying it back later at a lower price and earning a profit. Short-sellers often borrow stock to make good their trades.Short-sellers have exacerbated the financial crisis because their selling actions have pushed stock prices down very sharply.
Hedge funds: They're private, barely regulated investment funds that manage assets using high-risk, high-return strategies. They typically borrow money ("leverage") to eke out bigger returns and are often blamed for indiscriminate short-selling.