When I enter small decimal values (decimal with more than 5 leading zeroes like 0.0000001), the value seems to convert to scientific notation, although incorrectly.
You can see this fiddle:
http://jsfiddle.net/h8m8n6p7/1/
Notice the hardcoded numbers render correctly but when you edit the cells in the far right column, you get different behaviors. Numbers like 0.000006 are fine but 0.0000007 convert to 7e-7 (rendered in the cell as -77.0000000… depending on your numeric format pattern. This seems to happen for numbers with leading zeroes. Notice that 0.12345678 renders fine.
This seems wrong for two reasons: it should not be converting to scientific notation and certainly not rendering as the complete wrong number.
Not sure if this is HOT or numbro or just how the browser/ES5/6 handles small numbers.
HOT Version 3.0 CE and Pro in Chrome 66 64-bit (both Windows and Mac OS X)