How does the if statement know to continue adding from day 7 amount for the solution?

1. I am seeking to understand why my code doesn't work, please explain the logic behind my algorithm being flawed.

2. why on the solution code the nested-if statement knows to continue adding from the loss on day 7 on without specifing to add the investment amount.

You put 1000 dollars into a new cryptocurrency. Good luck!
Over ten years, the value of the investment increases by 5% each year.
In the seventh year, the investment loses 75% instead of increasing. Eeek!
Use a for loop to log how many years it has been and how much the investment is worth for each year.

let investment = 1000;

/// MY SOLUTION ///

const interest = .05;  
let balance = investment + (investment * interest);

for (i = 1; i < 11; i++){  
  if (i === 7){  
  balance = balance * -.75;  
  } else if (i < 7 || i > 7) {  
    balance = balance * i;  
  }    
  console.log("Year " + i + " investment amount $" + balance);  
}  

/// SOLUTION ///

for (i = 1; i < 11; i++){  
   if (i === 7){  
       investment = investment * .25;  
   } else {  
      investment = investment * 1.05;  
   }   
    console.log("It has been " + i + " years and we have $" + investment + " left");  
 }