Previously, customers could generally choose to route their own order to a PTS (an alternative trading venue), with only limited exceptions. Now, the company has added a blanket rule that customers can only choose a PTS for Tokyo-listed stocks that the company itself has designated as eligible. This gives the company more control over which stocks you can route to a PTS, potentially reducing your execution choices, though it may also reflect real technical/liquidity limits on which PTS venues actually support which stocks.
“なお、PTSを指定できる銘柄は東京証券取引所に上場する銘柄のうち当社が指定する銘柄に限ります。”
What you can do — If you regularly direct orders to a PTS for non-Tokyo-listed stocks, check with Rakuten Securities or their website to confirm whether your usual stocks are still eligible before placing future PTS-directed orders.