public List <string> tradeCategories(List <Trade> trades)
{
Portfolio portfolio = new Portfolio();
portfolio.portfolio = new List <Trade>();
foreach (var item in trades)
{
portfolio.portfolio.Add(item);
}
List <string> ReturnTradeCategories = new List <string>();
ReturnTradeCategories = _trade.tradeCategories(portfolio.portfolio);
return(ReturnTradeCategories);
}