	June 30,		December 31,
(US$ in millions)	2016		2015
Unrealized gains on derivative contracts, at fair value	$	2,965	$	1,456
Prepaid commodity purchase contracts (1)	415		287
Secured advances to suppliers, net (2)	240		521
Recoverable taxes, net	323		364
Margin deposits	595		467
Marketable securities, at fair value and other short-term investments	215		234
Deferred purchase price receivable, at fair value (3)	103		79
Prepaid expenses	213		132
Other	325		359

Total	$	5,394	$	3,899

⁽¹⁾

Prepaid commodity purchase contracts represent advance payments against fixed price contracts for future delivery of specified quantities of agricultural commodities.

⁽²⁾

Bunge provides cash advances to suppliers, primarily Brazilian farmers of soybeans and sugarcane, to finance a portion of the suppliers’ production costs. Bunge does not bear any of the costs or risks associated with the related growing crops. The advances are largely collateralized by future crops and physical assets of the suppliers, carry a local market interest rate and settle when the farmer’s crop is harvested and sold. The secured advances to farmers are reported net of allowances of $2 million and $2 million at June 30, 2016 and December 31, 2015, respectively.

Interest earned on secured advances to suppliers of $7 million and $9 million for the three months ended June 30, 2016 and 2015, respectively, and $18 million and $20 million for the six months ended June 30, 2016 and 2015, respectively, is included in net sales in the condensed consolidated statements of income.

⁽³⁾

Deferred purchase price receivable represents additional credit support for the investment conduits in Bunge’s accounts receivables sales program (see Note 12).