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.
What It Is. The bid price is the highest price that a prospective buyer is willing to pay for a specific security. The ask price, is the lowest price acceptable to a prospective seller of the same security. The highest bid and lowest offer are quoted on most major exchanges, and the difference between the two prices is called the bid-ask spread. How It Works Unlike shopping for groceries, in the stock market the buyer also has a say in what price they will pay for a security. The price set by the buyer is the bid price.