At December 31, 2020, the available-for-sale debt portfolio for Pronghorn Corp. is as follows. Unrealized Gain (Loss) Securities Cost Fair Value Good Co. Bonds $29,400 $27,300 $(2,100 ) Home Co. Bonds 31,400 33,400 2,000 Grand Inc. Debentures 43,900 44,800 900 104,700 105,500 800 Before an adjusting entry on December 31, 2020, the fair value adjustment account contained a credit balance of $520. Pronghorn Corp. reported net income of $78,800 for 2020. (a) Prepare the adjusting entry at December 31, 2020, to report the portfolio at fair value. (Credit account titles are automatically indented when amount is entered. Do not indent manually. If no entry is required, select "No Entry" for the account titles and enter 0 for the amounts.)