Cardiac tamponade can occur due to: 1  Dissecting aortic aneurysm (thoracic) 2  End-stage lung cancer. 3  Heart attack (acute MI) 4  Heart surgery. 5  Pericarditis caused by bacterial or viral infections. 6  Wounds to the heart.
Bid vs. ask and why yields matter. With many investments, the concept of bid and ask applies to prices. The bid price is what a buyer is willing to pay for a security, while the ask price is what a seller is willing to accept for the same security. The difference between those two numbers is known as the bid-ask spread, and in general, the narrower that spread, the more liquid the market is.
This is the opposite of the ask, which stipulates the price a seller is willing to accept for a security and the quantity of the security to be sold at that price. 1. An example of a bid in the market would be $23.53 x 1,000, which means that an investor is willing to purchase 1,000 shares at the price of $23.53. If a seller in the market is willing to sell that amount for that price, then the transaction is completed. 2. Market makers are vital to the efficiency and liquidity of the marketplace. By quoting both bid and ask prices on the market, they always allow investors to buy or sell a security if they need to.