Assertion failure in UITableView configureCellForDisplay:forIndexPath:

I'm not sure where the error is here, having looked at other similar issues. I received an Assertion failure.

Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: UITableView dataSource must return a cell from tableView:cellForRowAtIndexPath:

I think it is something simple but hope someone can help.

Below is my code:

#import "StockMarketViewController.h"

@interface StockMarketViewController ()

@end


@implementation StockMarketViewController
@synthesize ShareNameText, ShareValueText, AmountText;
@synthesize shares, shareValues;


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section;
{
    return [shares count];

}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath;
{
    UITableViewCell * cell = [tableView dequeueReusableCellWithIdentifier:@"cell"];



    NSString *currentValue = [shareValues objectAtIndex:[indexPath row]];
    [[cell textLabel]setText:currentValue];
    return cell;

}