Rolled Up-and-Out the Covered Calls Position in Dexcom Inc.

The Covered Calls Advisor Portfolio had a Covered Calls position in Dexcom Inc. (ticker DXCM) that has an options expiration date today at the $64.00 strike price.  Dexcom's stock price had increased slightly from $66.66 when it was originally purchased on December 23rd, 2025 to $67.55 today when I decided to continue with this Covered Calls position with a one-week roll up-and-out transaction to the monthly January 16th, 2026 $65.00 strike price.  To accomplish this rollout, a debit spread transaction was executed by simultaneously buying-to-close 3 January 9th, 2026 $65.00 Calls @ $3.60 per share (so only $.05 time value remaining since the stock price was $67.55 when this transaction was executed) and selling-to-open 3 January 16th, 2026 $65.00 Calls @ $4.21 per share--a net credit of $.61 per share to roll-up by $1.00 per share (from $64.00 to $65.00).  

As detailed below, a potential return-on-investment result is +4.0% absolute return-on-investment (equivalent to +69.7% annualized return-on-investment over the 24 days duration of this Covered Calls position) if the stock is assigned on the January 16th, 2026 options expiration date.

Dexcom Inc. (DXCM) -- Rolled Up-and-Out this Covered Calls Position
The original simultaneous buy/write transaction today was as follows:
12/23/2025 Bought 300 Dexcom Inc. shares @ $66.66
12/23/2025 Sold 3 DXCM 1/9/2026 $64.00 Call options @ $3.60 per share
Note: the Implied Volatility of the Calls was 33.1 when this transaction was executed.  As I prefer, this value exceeds that of the S&P 500 Volatility Index (VIX) which is currently at 14.1.
1/9/2026 Dexcom Covered Calls rolled up-and-out by buying-to-close the three 1/9/2026 $64.00 Calls at $3.60 per share and simultaneously selling three 1/16/2026 $65.00 Calls at $4.21 per share, so a net credit of $.61 per share.

A possible overall performance result (including commissions) for this Dexcom Covered Calls position if assigned on the options expiration date is as follows:
Covered Calls Cost Basis: $18,920.01
= ($66.66 - $3.60) * 300 shares + $2.01 commission

Net Profit Components:
(a) Options Income: +$1,256.97
= ($3.60 - $3.60 +$4.21) * 300 shares - $6.03 commissions
(b) Dividend Income $0.00
(c) Capital Appreciation (If Dexcom shares assigned at $65.00 strike price at the 1/16/2026 options expiration date): -$498.00
+($65.00 - $66.66) * 300 shares

Total Net Profit (If Dexcom shares assigned at the $65.00 strike price at the 1/16/2026 options expiration date): +$758.97

= (+$1,256.97 options income + $0.00 dividend income - $498.00 capital appreciation)

Absolute Return-on-Investment (If DXCM shares assigned at $65.00 strike price on Jan. 16th, 2026 options expiration date): +4.0%

= +$758.97/$18,920.01

Annualized Return-on-Investment (If Dexcom stock assigned at $65.00 at the 1/16/2026 options expiration date): +69.7%

= (+$758.97/$18,920.01) * (365/24 days)