Amazon officially assumed control of Whole Foods Market on Monday and by noon, channel checks at WFM stores revealed that its new tech overlords had already slashed prices by nearly 50%, sending bonds of its grocery-chain rivals reeling as grocers confronted a new dilemma: either slash prices to the point of unprofitability, or hold the line and risk seeing sales evaporate.

And as bonds of even highly rated grocery chains have underperformed this week,Bloomberg is questioning whether the WFM acquisition has fundamentally changed market dynamics in what was previously an island of stability in a retail sector beset by bankruptcies.

Even before the WFM acquisition, the industry experienced the first signs of strain as Amazon launched its Amazon Fresh grocery service and Wal-Mart started stocking up on reasonably priced organics – factors that contributed to the massive drop in WFM’s market cap, allowing Amazon to scoop it up for less than $14 billion.

Prior to this, the conventional wisdom dictated that grocers were impervious to the onslaught of e-commerce that was decimating industries such as clothing and electronics. Investors reasoned that consumers would probably balk at buying perishable goods like food online.

But Amazon, with its seemingly infinite capacity to slash prices and brook losses, has created new risks for Whole Foods’ rivals.

Apollo Global thought buying North Carolina-based Fresh Market for the “every day low price” of $1.4 billion would be a turnaround slam dunk after its success with Sprouts Farmers Markets. One year later, the future profitability of that deal is in doubt, and that uncertainty is being reflected in the price.

 The bonds that financed Apollo Global Management’s purchase last year of upscale grocer Fresh Market plunged to new lows this week. The cost of buying contracts to protect against a default in Albertsons Cos.’s debt has jumped. Bonds of Bi-Lo Holdings have lost almost half their value this year.”