I am a new pond owner and we have about 10 4-6 inch long goldfish in a large pond. One shubunkin is frequently chased and almost held down by 2 or 3 of the other fish. They were all placed in the pond within a couple days of each other and some came out of the same tank at the pet store. What is going on?

That's breeding behavior in goldfish. Your shubunkin is a female and probably full of eggs. She is chased by the males who fertilize her eggs. If they're bullying her too much, you may have to separate her.... Can you float a cage of some sort in the pond for her? You can fashion one out of plastic mesh from a craft store. I've even seen people use plastic laundry baskets with pool floaties on them to make it float to house a female that's being hassled too much.

How big is your pond? In my pond I have anacharis for the fish to spawn in.... I got four or five very pretty little comets from the spring spawn. They're about 2-3 inches long now.

yeah your shubie is most likely a girl and being chased becasue of breeding behaviour.

how big is your pond?