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.
Bid/Ask Price. A currency exchange rate is typically given as a bid price and an ask price. The bid price is always lower than the ask price. The bid price represents what will be obtained in the quote currency when selling one unit of the base currency. The ask price represents what has to be paid in the quote currency to obtain one unit of the base currency.