$ cat cards/john-terry-tt-a-2010/faq/completion-faq-26.md

What happens to the checklist completion percentage if I trade away a card?

card: John Terry TT-A (2010) · category: completion

[Concise Summary]

Trading away your only copy of a card will decrement your collection count and reduce your overall completion percentage.

[Structured Data Grid]

Inventory Threshold	≥1 copy required
Percentage Impact	-0.15% per card lost
Checklist Status Flag	Dynamic state check
Recommendation	Only trade duplicates

Detailed Investigation & Analysis

The companion tracker calculates completion based on active inventory status. If your inventory falls below 1 copy for code TT-A, the slot is flagged as uncompleted. Keep a duplicate swap buffer to avoid progress regression.

Additional notes for collectors: Ensure checklist entries are verified before confirming trades. Standard trade ratios are calculated relative to card popularity.

[Album Context Specs]

Card Code	TT-A
Official Name	John Terry TT-A (2010)
Estimated Value	$0.87 USD
Album Section	England (2010)
Completion Mode	Required Checklist Item