before I answer your question, I have a question, where do you have this huge amount of BTC? And at what price do you buy it?
No one gives away 10 000 BTC to anyone - and it’s also completely ridiculous to believe that the OP bought them. I'd conclude that the OP actually bought/got some fake wallet (maybe watch-only wallet), that maybe it's actually $10 000 - or that it's just a regular troll.
If I had so many BTCs and wanted to sell them, I’m sure I wouldn’t sell them all at once - and the best option would be to do it over OTC - directly at one of the respectable crypto exchanges.