	March 31,		December 31,
(US$ in millions)	2017		2016
Unrealized gains on derivative contracts, at fair value	$	1,907	$	1,327
Prepaid commodity purchase contracts (1)	252		273
Secured advances to suppliers, net (2)	637		601
Recoverable taxes, net	448		467
Margin deposits	326		251
Marketable securities, at fair value and other short-term investments	151		94
Deferred purchase price receivable, at fair value (3)	95		87
Prepaid expenses	156		148
Other	475		397

Total	$	4,447	$	3,645

(1)

Prepaid commodity purchase contracts represent advance payments against 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 operational 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 $10 million at March 31, 2017 and $1 million at December 31, 2016. There were no significant changes in the allowance at March 31, 2017 and December 31, 2016, respectively.

Interest earned on secured advances to suppliers of $16 million and $11 million, respectively, for the three months ended March 31, 2017 and 2016 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).