NEW YORK (AP) -- Moody's Investor Services downgraded RadioShack Corp.'s long-term senior unsecured rating and short-term commercial paper Monday on lackluster sales and operations. The ratings agency lowered the electronics retailer's senior unsecured rating to "Ba1" from "Baa3." The move means the company's senior unsecured rating is no longer investment grade. Moody's also cut RadioShack's commercial paper rating to "Not Prime" from "Prime-3."

Sometimes you have to wonder what exactly rating agencies like S&P and Moody's are looking at when they change corporate bond ratings. This news isn't material for RadioShack (RSH) common stockholders, but still, it doesn't make sense.

As I pointed out recently, the RadioShack turnaround is on solid ground. Despite the surge in earnings at the company, Moody's is looking at sales numbers, not profitability and balance sheet metrics when rating the company's debt. Not only have most equity analysts missed the huge run in RSH shares, but it appears debt analysts are pretty clueless as well.

RSH has had a huge run, so I wouldn't be aggressively buying at the current price above $26 per share. That said, a credit downgrade to below investment grade seems to be a strange thing to go ahead with when operations are improving.

Full Disclosure: Long shares of RSH at time of writing