Danke, du hast mir sehr geholfen.

Leider ist "silent reserves" nicht richtig.

Der Fachausdruck hierfür ist hidden reserves.

Resources not listed on a balance sheet, such as land or building shown at a value less than its market value.
http://www.businessdictionary.com/definition/hidden-reserve.html

Siehe auch:
http://financetraining.com/hidden-reserves-definition/

I beg to differ, since "hidden" leads the reader into the wrong direction.

"silent" means "not visible" (and "presently not taxable"); that's a completely different story.

The confusion may stem from the fact that the system of "stille Reserven" is not known in the English speaking world. All the more is is important that a telling term be used.

I second hidden reserves ("hidden assets" or "undisclosed reserves" are also possible).

"Silent reserve" is wrong.