understood / understand

[joham]

Sharp losses are to be expected and even considered normal by those who have studied and understand/understood the long history of stock markets.

Are both understood and understand correct in contexts like this?

Thank you in advance.

[Allen165]

Sharp losses are to be expected and even considered normal by those who have studied and understand/understood the long history of stock markets.

Are both understood and understand correct in contexts like this?

Thank you in advance.

NOT A TEACHER.

Yes, they're both correct, but I prefer "understand."

[albertino]

NOT A TEACHER.

Yes, they're both correct, but I prefer "understand."

Any reasons for your preference?

[emsr2d2]

Sharp losses are to be expected and even considered normal by those who have studied and understand/understood the long history of stock markets.

Are both understood and understand correct in contexts like this?

Thank you in advance.

I would use understand. The studying took place in the past but the person still (now) understands the stock market.

I have studied and understand Spanish.
He has studied and understands physics.

I think "I have studied and understood Spanish" sounds as if I understood it in the past but perhaps I no longer understand.

[albertino]

I would use understand. The studying took place in the past but the person still (now) understands the stock market.

I have studied and understand Spanish.
He has studied and understands physics.

I think "I have studied and understood Spanish" sounds as if I understood it in the past but perhaps I no longer understand.

Thank you for your explanation.
However, could I say I studied Spanish sometime in the past, thereby from then on up to now(have understood) I understand Spanish?

[emsr2d2]

Thank you for your explanation.
However, could I say I studied Spanish sometime in the past, thereby from then on up to now(have understood) I understand Spanish?

You could say "I studied Spanish five years ago and have understood everything that has been said to me in Spanish since I completed my studies." That's a very wordy example but still correct.

[albertino]

Thank you again.