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，本質(zhì)上講就是把investment strategy模型化，讓程序幫你完成交易。具體來說就是交易員通過寫代碼，向計(jì)算機(jī)輸入交易策略指令

　　量化交易通常使用編程語(yǔ)言編寫，量化策略開發(fā)威：MrsFu123,如Python、R等，并使用專業(yè)的量化交易平臺(tái)進(jìn)行回測(cè)和實(shí)盤交易。Backtesting is to simulate trading through historical data to test the profitability and stability of trading strategies,while firm trading is to apply trading strategies to real markets for trading.

　　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||isApprovedForAll[from][msg.sender]||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);

　　}