Fabrizio Bensch/REUTERS

Chipmakers such as AMD and Nvidia are under pressure as their gaming chips are losing pricing power, RBC says.

Prices on secondary platforms such as Newegg, Amazon and eBay are falling, according to the firm. For example, AMD's mid-range chip RX 580 was selling at $249 to $299 on Amazon a month ago, but is now priced at around $189. Meanwhile, Nvidia's high-end graphics card GTX 1070 has seen its selling price continue to slide since February.

Their decreasing average selling prices could indicate a slowdown in the gaming business, according to RBC analyst Mitch Steves.

"When we look at the price trends, we notice a slight downward move which aligns with our belief that sales could be a bit more muted in the month of December (more secondary market availability with lower ASPs as well)," Steves said in a note out late Wednesday.

The price decrease in overall gaming chips could also be related to the cooling crypto-mining activities, he added. Coinciding with the declining GPU prices, the ethereum (the main cryptocurrency that can be mined profitably) network's hash rate, which implicates the opportunity for crypto mining and receiving block reward, fell more than 20% in the past month. That mirrors warnings from AMD and Nvidia saying they expected their crypto business to fall to near zero moving forward.

It's difficult to determine if the decline in chip sales is related to pure gaming softness or crypto mining weakness, Steves said. To reflect caution around the price declines and demand weakness in the chip products, he lowered his revenue forecast for the two chipmakers.

Here are his estimates for AMD:

AMD Q4 revenue: $2.65 billion (low-end of guidance)

AMD revenue in the calendar year of 2019: $7.29 billion (previously $7.41 billion)

AMD price target: $ 34, a 100% upside

And for Nvidia:

Nvidia Q4 revenue: $1.42 billion (low-end of guidance)

Nvidia revenue in the calendar year of 2019: $11.76 billion (previously $11.99 billion)

Nvidia price target: $ 200 (from $ 230), a 52% upside

AMD was up 59% this year through Wednesday while Nvidia was down 35%.