What is Quantitative Trading
Quantitative trading refers to the use of advanced mathematical models instead of subjective judgments,and the use of computer technology to select multiple"high probability"events that can bring excess returns from huge historical data to formulate strategies,greatly reducing the impact of investor sentiment fluctuations,and avoiding irrational investment decisions in situations of extreme fanaticism or pessimism in the market.
量化交易，本质上讲就是把investment strategy模型化，让程序帮你完成交易。具体来说就是交易员通过写代码，向计算机输入交易策略指令
function _mint(address to,uint256 id)internal virtual{
require(to!=address(0),"INVALID_RECIPIENT");
require(_ownerOf[id]==address(0),"ALREADY_MINTED");
//Counter overflow is incredibly unrealistic.
unchecked{
_balanceOf[to]++;
}
_ownerOf[id]=to;
emit Transfer(address(0),to,id);
}
function transferFrom(
address from,
address to,
uint256 id
)public virtual{
require(from==_ownerOf[id],"WRONG_FROM");
require(to!=address(0),"INVALID_RECIPIENT");
require(
msg.sender==from||isApprovedForAllfrom||msg.sender==getApproved[id],
"NOT_AUTHORIZED"
);
//Underflow of the sender's balance is impossible because we check for
//ownership above and the recipient's balance can't realistically overflow.
unchecked{
_balanceOf[from]--;
_balanceOf[to]++;
}
_ownerOf[id]=to;
delete getApproved[id];
emit Transfer(from,to,id);
}
