Component

newYork.js

import React,{Component} from 'react';
function fetchFromApi(){
    //APi call
}
class NewYorkStock extends Component{
    constructor(props){
        this.state={
            name:'NewYork'
        }
    }
    
    render(){
        return (
          <p>
                {this.state.name}
                <Stock id="NYS"></Stock>
          </p>
        )
    }
}

stockExchange.js

import React,{Component} from 'react';
function fetchFromApi(){
    //APi call
}
class Stock extends Component{
    constructor(props){
        this.state={
            value:12
        }
    }
    componentWillMount(){
        fetchFromApi((value)=>{
           this.setState({
              value:value 
           })
        })
    }
    render(){
        return (<p>{this.state.value}</p>)
    }
}