Collateral

What it is:

Collateral is an asset pledged by a borrower to a lender, usually in return for a loan. The lender has the right to seize the collateral if the borrower defaults on the obligation.

How it works/Example:

Let's assume you would like to borrow $100,000 to start a business. Even if you have an excellent credit rating, a bank may be reluctant to lend you the money because it may be left with nothing if you default on the loan. Thus, the bank may require $100,000 of collateral in order to lend you the money. This collateral might consist of financial instruments, houses, cash, or even objects such as art, jewelry, or other items. You might also pledge your business receivables as well.          
 
If you do in fact default on the loan, the loan agreement gives the lender the right to seize and then sell the collateral in order to recover any outstanding balance.

Why it Matters:

Collateral is security, which is why collateralized loans often receive better interest rates than unsecured loans, since the lender bears less risk.
 
Although mortgages are one of the most common collateralized obligations (with the house being the collateral), many other kinds of lending circumstances require collateral. For instance, margin loans almost always require collateral. Frequently the collateral is the securities involved in the margin loan.
 
However, the type and amount of collateral required for a given loan is often a matter of negotiation between the lender and borrower. For instance, a lender might require a borrower to pledge any assets purchased during the loan period as additional collateral. In some cases, collateral for one obligation can also be collateral for other obligations (this is called cross-collateralization). This often occurs in real estate transactions, where a house collateralizes more than one mortgage.

Best execution refers to the imperative that a broker, market maker, or other agent acting on behalf of an investor is obligated to execute the investor's order in a way that is most advantageous to the investor rather than the agent.