Companies use Form 10-K to report their annual results.
 Companies use Form 10-Q to report their quarterly results.
 Companies use Form 8-K to disclose unscheduled material events, such as an acquisition, a new long term contract with a supplier, or quarterly conference call information.
 Companies use Form 4 to disclose insider trading transactions.

The bond yield is the coupon amount divided by the bond price (market value).
The bond coupon rate is the coupon amount divided by the par value (face value).

Triple witching is a one day event that happens on the third Friday of the last month in every calender quarter. That's March, June, September and December. On that day,  stock option contracts, stock index future contracts and stock index option contracts  expire on the same Friday.